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The Effect of Dietary Types on Gut Microbiota Composition and Development of Non-communicable Diseases

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26 July 2024

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26 July 2024

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Abstract
The importance of diet shaping the gut microbiota is well known and may help with improving the overall health of an individual. Many other factors also have an influence, such as genetics, age, exercise, antibiotic therapy, or tobacco use. The purpose of this review is to summarize how three distinct dietary types (plant-based diet, Mediterranean diet, and Western diet) affect the composition of gut microbiota and the development of non-communicable diseases (NCDs). PubMed, Web of Science and Scopus databases were used for searching papers with an emphasis on keywords ‘‘dietary pattern’’, ‘‘gut microbiota’’ and ‘‘dysbiosis’’. Plant-based diet and Mediterranean diet promote the production of beneficial bacterial products, and more microbial diversity and therefore are generally considered healthy dietary types. On the other hand, the Western diet is a typical example of an unhealthy approach to nutrition which leads to an overgrowth of pathogenic bacteria. Moreover, understanding the impact of diet on the modulation of gut microbiota may give rise to new therapeutical strategies.
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Subject: Public Health and Healthcare  -   Public, Environmental and Occupational Health

Introduction

The gut microbiota is a dynamic complex of microorganisms located in the gastrointestinal tract of humans [1]. It includes Bacteria, Archaea, viruses, protists and the relationship between microorganisms and the human host is mutually symbiotic and beneficial [2]. Representing a pivotal part of human body, gut microbiota plays significant role in nutrition and its physiology [3]. It is often times suggested to be a superorganism [4]. So far 2,172 species have been identified, with 12 distinct phyla. The majority of isolated species, 93,5% were Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes [5]. Firmicutes make up 65% of the total gut bacteria, Bacteroidetes 23%, Actinobacteria 5% and the fourth most represented phyla are Proteobacteria [6].
Diet is an essential factor for maintaining healthy status and preventing non-communicable diseases (NCDs). NCDs contain cancer, cardiovascular diseases, cognitive or metabolic impairments and they represent the majority of cases of mortality all around the world. It is suggested that diet has a great influence on the gut microbiota formation, which participates in the pathogenesis of NCDs [7,8]. Therefore, the aim of this review is to assess the relationship between 3 dietary types (plant-based diet, Mediterranean diet and Western diet) and the bacterial composition of the gut.
The purpose of this review is to summarize how three distinct dietary types (plant-based diet, Mediterranean diet, and Western diet) affect the composition of gut microbiota and the development of non-communicable diseases (NCDs). PubMed, Web of Science and Scopus databases were used for searching papers with an emphasis on keywords ‘‘dietary pattern’’, ‘‘gut microbiota’’ and ‘‘dysbiosis’’.

1. Composition of Gut Microbiota in the Gastrointestinal Tract

The distribution, quantity and type of microorganisms vary through the digestive tract. Only a little number of species appear in the stomach and small intestine. The majority populate the colon, which is located at the distal part of the digestive tract [9]. This is due to different physiology, pH, accessibility of substrates, oxygen partial pressure, flow rate of digestion and host secretions [10]. At least 700 different bacterial species are present in the human mouth cavity [11]. More than 94% is comprised of 6 phyla, Bacteroidetes, Firmicutes, Fusobacteria, Actinobacteria, Proteobacteria and Spirochaetes. The distribution of bacteria is modified by saliva, soft and hard tissue surfaces. More essentially, the hard surface of the tooth enables the formation of biofilms, which establish a steady environment for the bacterial growth [12]. In oesophagus, the most abundant genus is Streptococcus [13]. It is suggested that healthy stomach microbiota is mostly formed by Prevotella, Veillonella, Streptococcus, Haemophilus and Rothia. In addition, Bacteroidetes, Firmicutes, Fusobacteria, Actinobacteria and Proteobacteria were also found [14]. People, who tested positive for Helicobacter pylori had this bacterium as the most represented. However, the presence of Helicobacter pylori does not affect the microbial diversity of stomach [15].
The small intestine microbiota is less diverse and numerous than in the colon, with a biological mass of 103-107 microbial cells per gram of intestinal tissue, mainly because of lower pH, pancreatic peptides, bile acids or quicker transit time. It is assumed, that the most abundant phyla are Proteobacteria and Firmicutes, which can withstand these factors [16]. Anaerobic conditions of the colon provide a good environment for anaerobic microorganisms to grow [17]. The most represented bacterial phyla are Bacteroidetes and Firmicutes, which together make up 90% of the total bacteria population [18]. During life, the ratio between Bacteroidetes and Firmicutes varies, which can implicate the health of an individual. In terms of density, dominant bacterial genera, Bacteroides, Bifidobacterium, Eubacterium, Clostridium, Propionibacterium, Peptostreptococcus and Ruminococcus account for 109 of bacterial cells/gram of colon tissue [19]. There are also pathogenic bacteria present in the colon, namely Escherichia coli, Vibrio cholerae, Bacteroides fragilis, Salmonella enterica and Campylobacter jejuni and they form around 0.1% of the total bacterial population [20].

2. Function of Gut Microbiota

Gut microbiota has the ability to break down dietary fibre (oligosaccharides, polysaccharides, pectin, lignin, and resistant starches). By doing so, it generates short-chain fatty acids (SCFA), namely acetate, butyrate and propionate [21,22]. SCFA are absorbed in the gastrointestinal tract (GIT) and represent a valuable source of energy for host cells [23]. SCFA also has a variety of different effects, for example regulation of gene expression, apoptosis, chemotaxis, activation of gluconeogenesis and possibly regulation of appetite or its importance in the correct function of epithelial cells in the GIT [24,25,26]. Acetate was reported to be involved in the production of IgA by intestinal B-cells and IgA plays a crucial role in the toleration of gut bacteria and fighting against pathogenic bacteria [27]. Essential vitamins are yet another critical product of gut bacteria, such as vitamin K and several vitamins from the B group [28]. Furthermore, the gut bacteria can break down primary bile acids, transforming them into secondary bile acids, which can be reabsorbed [29]. The gut microbiota is also associated with the activation of polyphenols. After the activation, polyphenols are absorbed in the portal system [30].
It has been discovered that gut microbiota is connected to the brain. The axis between the gut and brain is a two-way communication, which is made of a network linking the central, autonomic, enteric nervous system and the hypothalamic pituitary adrenal system. It has been claimed that the axis affects multiple mechanisms, such as satiety and digestive functions, also behaviour and mood can be influenced, because the gut microbiota is able to modulate the serotoninergic system [31,32].

3. Factors Influencing the Gut Microbiota

The gut microbiota is at early stages of life influenced by the mother’s microbiota, but various factors shape it later in life, for instance infections, the immune system, diet or the use of medication. Genetics play an essential role in the formation of gut microbiota and several bacterial species are heritable, such as Actinobacteria and Firmicutes. This can be demonstrated in monozygotic and dizygotic twins. Both types of twins, when sharing the same environment show differences, but the difference between the gut microbiota of monozygotic twins is smaller [33]. Age is another important factor in gut microbiota composition. In infants, the gut microbiota lacks diversity when compared to adults. There is a large influx of bacteria until about 3 years of age when the gut microbiota starts to develop the adult characteristics [34]. This can be justified by the transition from a diet based on milk into a solid diet [35]. In adult humans, the structure and function of gut microbiota stay stable, but events such as diseases and antibiotic treatments may cause an alteration by changing bacterial composition and transferring genes of antibiotic resistance [1,36,37]. In the elderly population (over 65 years old), bacterial diversity is lower than in adults and the facultative anaerobic bacteria grow at the expense of useful bacteria [38].
Alcohol, smoking and exercise represent other determinants in shaping the gut microbiota. Alcohol promotes dysbiosis through two mechanisms: a change in gut microbiota composition and a reduction of nutrient absorption. Smoking as a risk factor acts in many ways. For instance, by modifying pH, oxygen levels and production of acid in the gastrointestinal tract. Tobacco is also an immunosuppressant. Exercise can enhance the diversity of gut microbiota and is even suggested as a remedy to dysbiosis-related chronic illnesses. However, it is difficult to prove the beneficial effects of exercise on the gut microbiota of athletes, since most of them have a distinct diet [39,40,41,42,43,44,45].
Diet and geography are important factors involved in the diversity of gut microbiota [46]. When comparing industrialized and non-industrialized countries, there is a greater Bacteroidetes to Firmicutes ratio [44]. Another division is by using enterotypes. Enterotype 1, characterized by an abundance of Bacteroides, enterotype 2, rich in Prevotella and enterotype 3, where Firmicutes are large in number, especially Ruminococcus [47]. Highers altitudes suit anaerobic bacteria and during cold environmental stress, there is a change in Bacteroidetes versus Firmicutes ratio, in favour of Firmicutes [48,49].

4. Diseases Related to Gut Microbiota

Dysbiosis is a term, that indicates the change and imbalance of the gut microbiota composition, which can lead to various illnesses [50]. Gastrointestinal diseases, for example Irritable bowel syndrome (IBS) are affected by gut microbiota by many mechanisms. There is a disruption in the gut-brain axis, changed motility of GIT, raised visceral sensitivity and intestinal barrier function is also modified [51]. In terms of gut bacteria composition of IBS patients, Bifidobacterium and Faecalibacterium populations were reduced. On the other hand, Proteobacteria, Bacteroides and Lactobacillacae were in higher numbers in contrast to the control group [52]. Inflammatory bowel disease (IBD) consists of Crohn's disease and ulcerative colitis [53]. Numerous changes in the gut microbiota of IBD patients have been reported, namely a higher abundance of Candida tropicalis, Escherichia coli, and a decrease in Firmicutes, Bacteroidetes or Faecalibacterium prausnitzii in comparision with the control group [44,54,55]. The pathogenesis of colorectal cancer (CRC) is characterized by a greater number of pathogenic bacteria. For example, Bacteroides fragilis and Escherichia coli promote a chronic inflammation of intestinal tissue, which can lead to the development of CRC [56].
The gut microbiota possesses multiple mechanisms, that can affect the development of obesity, such as modulating appetite, energy absorption, inflammation or fat storage [57]. It was believed, that Bacteroidetes/Firmicutes ratio changes during the pathogenesis of obesity, however this has been recently proven untrue, as there is no microbiological connection to human obesity [58]. Dysbiosis of the gut microbiota is a factor connected to the pathogenesis of Diabetes mellitus (DM), both type 1 and type 2 [59]. To be more specific, type 1 DM patients exhibit a higher abundance of Ruminococcus and Bacteroides, with a lower proportion of Prevotella and Clostridium as opposed to the control group. Similarly to obesity, in type 2 DM there is a drop in Akkermansia and Bifidobacterium amounts [60,61,62]. Furthermore, type 2 DM represents a good environment for the growth of opportunistic pathogens, for example Escherichia coli or Clostridium symbiosum [63].
It is suggested that the gut-brain axis might be associated with neuroinflammation, a process, that leads to the loss of neurons, which is typical for Alzheimer disease (AD) and Parkinson disease (PD). PD patients had a higher abundance of Enterobacteriaceae and reduced populations of Prevotellaceae. AD is influenced by pathogenic bacteria like Mycobacterium tuberculosis, Staphylococcus aureus or Salmonella spp. [64,65]. Pathogenic bacteria also seem to be involved in the pathogenesis of depression and anxiety disorders, namely Enterobacteriaceae and Desulfovibrio [66]. Autism spectrum disorder (ASD) is another neurological disability, in which the dysbiosis of gut microbiota is suggested to be involved, but the evidence is conflicting [67].
In addition, gut bacteria are also affiliated with other diseases, for example cardiovascular disorders (by producing SCFA), and autoimmune disorders like multiple sclerosis or rheumatoid arthritis (by altering immune responses) [68,69].

5. The Effect of Diets on Gut Microbiota Composition

Plant-based diets are comprised of fruits, vegetables, seeds, nuts, legumes, whole grains and herbs [70]. There are multiple forms of plant-based diets, which differ in restricted components. Flexitarians rarely consume meat, while pescatarians eat fish and seafood as their only sources of meat. Ovolactovegetarians exclude meat products, but consume dairy or eggs and lastly, vegans have a diet, where every component is plant-based [71]. The idea of the Mediterranean diet is based on the diet of countries located near the Mediterranean Sea [72]. It is mostly a plant-based diet with olive oil as a main source of fat. In terms of animal products, the consumption is moderate [72,73]. The Western diet is often considered an unhealthy diet and is defined by excessive consumption of processed and refined foods, simple sugars, sweets or animal fats. In addition, consumption of fruits, vegetables, nuts and whole grains is insufficient [6,74,75] (Table 1, Table 2).
In 2023, there was a systematic review done by Sidhu et al. about plant-based diet influence on the composition of gut microbiota and the benefits of plant-based diet in inflammatory and metabolic disorders. They included randomized control trails, non-randomized control trails and pre-post interventions, that highlighted the impact of plant-based diet on gut microbiota. Systematic review consisted of 12 interventional studies, that were incorporated with a total of 583 participants, aged between 21 and 61 years old, both men and women. In terms of health status, participants were healthy, obese, rheumatoid arthritis patients and individuals with cardiovascular risk. They followed a plant-based diet for certain amount of time, ranging from 5 days to 13 months. A higher abundance of Ruminococcaceae and a decreased population of Bacteroidaceae were revealed in individuals following plant-based diets. However, differences between vegan and vegetarian diet have been discovered. Vegans had Coprococcus and Faecalibacterium in higher numbers. On the other hand, in vegetarians these bacteria populations decreased. It has been also found that rheumatoid arthritis patients improved after following the plant-based diet together with patients with cardiovascular disorders, whose lipid profiles and blood pressures were more optimized. The positive outcomes might be related to metabolic products like SCFA or TMAO (Trimethylamine N-oxide) [76]. SCFA, which are produced by the degradation dietary fibres and carbohydrates, play an important role in immune, metabolic, and neural systems [25]. Consumption of vegetables and fruits affect levels of SCFA highly [76]. Elevated TMAO level is associated with inflammation and metabolic diseases, mainly obesity and diabetes. Plant based diet has been also shown to decrease levels of TMAO [77] (Table 1, 2).
Trefflich et al. published a systematic review related to the relationship between gut microbiota composition and vegan or vegetarian diet in comparison to omnivores. 16 studies were included in the final review with cross-sectional design. Apart from 1 study they consisted of men and women of age between 18 and 72. Total number of participants were 1229, out of which were 498 omnivores, 389 vegetarians and 342 vegans, which followed a vegetarian or vegan diet for more than a month. Vegans had higher levels of Bacteroidetes in contrast to omnivores, Firmicutes levels were similar. An increase in Actinobacteria populations in vegetarians also have been reported. In vegans, a decrease in Proteobacteria and an increase in Verrucomicrobia have been found, both compared to omnivores [78]. In addition, Losno et al. investigated the composition of adult gut microbiota and compared vegans with omnivores. They found, that Bacteroidetes were in higher numbers in vegans when compared to omnivores. Within Bacteroidetes, vegans exhibited an increase in Prevotella, but Bacteroides results were conflicting. On the other hand, Bifidobacteria and Enterobacteria were less abundant in the vegan population when compared to omnivores. Interestingly, also lower abundance of Staphylococcus, Streptococcus and Corynebacteria were present in a group following a vegan diet [79] (Table 1).
Kimble et al. assessed the effect of Mediterranean diet on gut bacteria diversity, abundance and its metabolic products. The systematic review evaluated 34 studies with a total of 4526 participants aged 22 to 95 years old. The majority of participants were healthy, but individuals with other medical conditions were also included. 17 studies were observational and the other 17 were randomized control trials. In terms of observational studies, 3 were prospective and 14 were cross-sectional studies. Regarding to bacterial diversity, an increase in Bacteroidetes and a decrease in Firmicutes populations in those, who followed the Mediterranean diet have been reported. Moreover, a higher abundance of Faecalibacterium prausnitzii has been found [73]. Three fundamental elements of the Mediterranean diet are fibre, extra virgin olive oil (EVOO) and polyunsaturated fatty acids (PUFA) [72]. It has been demonstrated that consumption of EVOO leads to an expansion of Lactobacillus and reduced growth of pathogenic bacteria [80]. Similarly, PUFA has also an impact on anti-inflammatory processes with its cardioprotective properties [6,72]. PUFA ω-3 has a beneficial effect on Bifidobacterium growth. On the other hand, ω-3 have an opposite effect on Faecalibacterium populations [6,81]. In terms of fibre, it is metabolized by gut bacteria and SCFA are synthetised, which have anticancer and cardioprotective properties [72]. Similarly to plant-based diet, TMAO levels are also decreased [82]. In addition, this diet has also a positive role in reducing the risk of the development of diabetes mellitus and other metabolic disorders [83]. So et al. conducted a systematic review and a meta-analysis, where they analyzed the impact of dietary fibre on the composition of gut microbiota but did not identify any alteration of the alpha diversity. However, an increase in Bifidobacterium and Lactobacillus has been discovered [84]. Other beneficial effects are attributed to a decreased oxidative state, inflammation and positive impact on metabolic health represented by increased levels of Eubacterium rectale and Clostridium leptum, bacteria producing short-chain fatty acids, raising levels of Bacteroides, Bifidobacteria and Faecalibacterium prausnitzii species, and lower levels of Blautia species and Firmicutes [85] (Table 1, 2).
Health consequences of the Western diet are numerous, such as dyslipidemia, insulin resistance, systemic inflammation, overactivation of sympathetic and renin-angiotensin systems or altering the gut microbiota [75]. A major effect of the Western diet on the gut microbiota is due to a high consumption of processed and ultra-processed foods. It has been discovered that various factors like acellular nutrients, artificial sweeteners and emulsifiers can have a negative impact on the gut microbiota and thus promote dysbiosis [86]. Another important part of the Western diet is the excessive consumption of fats. Wolters et al. conducted a systematic review of the impact of fat on the composition of gut microbiota. They incorporated a total of 15 studies, out of which 9 were cross-sectional observational studies and 6 randomized control trials. The number of participants varied, cross-sectional studies included from 9 to 531 participants, randomized control trials from 20 to 88. 10 studies included men and women, 2 only men and 3 only women with mean age ranging from 8.1 to 63.3 years. Individuals followed a high-fat diet for 3 weeks up to a year. A reduced number of bacteria has been observed in individuals following the diet high in monounsaturated fatty acids (MUFA), however Prevotella, Enterobacteriaceae, Parabacteroides and Turicibacter populations have grown. The ratio between Bacteroidetes and Firmicutes was also changed, with an increase in Firmicutes and decreased levels of Bacteroidetes [87] (Table 1).
Other components of the Western diet might also have effects on gut microbiota, for instance refined carbohydrates, red meat and salt. A high-salt diet leads to a decrease in SCFA production and a reduced Lactobacillus abundance [6,88]. On the other hand, consumption of red meat leads to an increase in TMAO production [76]. The pathogenesis of CRC is highly influenced by the disproportionate consumption of red meat and processed meat. Dysbiosis of the gut microbiota might play a role in the CRC pathogenesis, namely an increased volume of Escherichia coli, Streptococcus bovis, Bacteroides fragilis and Fusobacterium nucleatum, which can create inflammation or alter the oncogenes and tumor-supressing genes [89]. Added sugars might also modulate the gut microbiota. An increase in Firmicutes among Bacteroidetes/Firmicutes ratio has also been described in connection to the consumption of sweetened beverages [90]. Negative effects on insulin metabolism are associated with higher levels of Clostridium bolteae and Blautia, which are linked with the consumption of mainly short fatty acids (SFA) in the diet [87] (Table 1, 2).

Conclusions

Plant-based diet and Mediterrean diet are rich in fibre and are linked to an increase in production of SCFA and lowering TMAO levels, which both have a great impact in improving cardiovascular and metabolic diseases. Moreover, there is an overall decrease in inflammation of the body. Mediterranean diet is also typical for its PUFA and EVOO content, which multiply the cardioprotective effect. Both dietary types also have a positive influence on bacterial diversity of the gut. In the contrary, the Western diet is characterized by high consumption of processed and ultra-processed food, fats, salt and red meat. As a result, it leads to lower levels of SCFA and higher levels of TMAO, an increase of the cardiovascular risk, insulin resistance, systemic inflammation or development of CRC. Bacterial diversity is reduced, which is linked to overgrowth of pathogenic bacteria.
Current scientific literature acknowledges plant-based diet and Mediterranean diet as healthy forms of diet compared to the unhealthy Western diet. It is a big challenge to further evaluate the relationship between dietary types and gut microbiota composition, since diet seems to be significant factor influencing it. Additionally, a healthy gut can prevent and improve the outcome of various NCDs, therefore targeting dysbiosis may provide valuable therapeutical effects.

Author Contributions

M.S, J.B., B.G. and L.H. wrote the manuscipt with the supervision and assistance of Ľ.A. All authors contributed to the final version and approval of the manuscript.

Funding

This work was supported by a grant KEGA No. 015UK-4/2022 Innovation of education in the field of health protection and promotion with an emphasis on e-learning and implementation of multimedia technologies

Conflict of Interest

The authors declare no conflict of interest.

References

  1. Thursby E, Juge N. Introduction to the human gut microbiota. Biochem J. 2017;474(11):1823-1836. Published 2017 May 16. [CrossRef]
  2. Rosenberg E, Zilber-Rosenberg I. Microbes Drive Evolution of Animals and Plants: the Hologenome Concept. mBio. 2016;7(2):e01395. Published 2016 Mar 31. [CrossRef]
  3. Qin J, Li R, Raes J, et al. A human gut microbial gene catalogue established by metagenomic sequencing. Nature. 2010;464(7285):59-65. [CrossRef]
  4. Salvucci E. The human-microbiome superorganism and its modulation to restore health. Int J Food Sci Nutr. 2019;70(7):781-795. [CrossRef]
  5. Hugon P, Dufour JC, Colson P, Fournier PE, Sallah K, Raoult D. A comprehensive repertoire of prokaryotic species identified in human beings. Lancet Infect Dis. 2015;15(10):1211-1219. [CrossRef]
  6. García-Montero C, Fraile-Martínez O, Gómez-Lahoz AM, et al. Nutritional Components in Western Diet Versus Mediterranean Diet at the Gut Microbiota-Immune System Interplay. Implications for Health and Disease. Nutrients. 2021;13(2):699. Published 2021 Feb 22. [CrossRef]
  7. Hills RD Jr, Pontefract BA, Mishcon HR, Black CA, Sutton SC, Theberge CR. Gut Microbiome: Profound Implications for Diet and Disease. Nutrients. 2019;11(7):1613. Published 2019 Jul 16. [CrossRef]
  8. Cena H, Calder PC. Defining a Healthy Diet: Evidence for The Role of Contemporary Dietary Patterns in Health and Disease. Nutrients. 2020;12(2):334. Published 2020 Jan 27. [CrossRef]
  9. Walter J, Ley R. The human gut microbiome: ecology and recent evolutionary changes. Annu Rev Microbiol. 2011;65:411-429. [CrossRef]
  10. Flint HJ, Scott KP, Louis P, Duncan SH. The role of the gut microbiota in nutrition and health. Nat Rev Gastroenterol Hepatol. 2012;9(10):577-589. Published 2012 Sep 4. [CrossRef]
  11. Arweiler NB, Netuschil L. The Oral Microbiota. Adv Exp Med Biol. 2016;902:45-60. [CrossRef]
  12. Zhang Y, Wang X, Li H, Ni C, Du Z, Yan F. Human oral microbiota and its modulation for oral health. Biomed Pharmacother. 2018;99:883-893. [CrossRef]
  13. Yang L, Lu X, Nossa CW, Francois F, Peek RM, Pei Z. Inflammation and intestinal metaplasia of the distal esophagus are associated with alterations in the microbiome. Gastroenterology. 2009;137(2):588-597. [CrossRef]
  14. Nardone G, Compare D. The human gastric microbiota: Is it time to rethink the pathogenesis of stomach diseases?. United European Gastroenterol J. 2015;3(3):255-260. [CrossRef]
  15. Bik EM, Eckburg PB, Gill SR, et al. Molecular analysis of the bacterial microbiota in the human stomach. Proc Natl Acad Sci U S A. 2006;103(3):732-737. [CrossRef]
  16. Martinez-Guryn K, Hubert N, Frazier K, et al. Small Intestine Microbiota Regulate Host Digestive and Absorptive Adaptive Responses to Dietary Lipids. Cell Host Microbe. 2018;23(4):458-469.e5. [CrossRef]
  17. Eckburg PB, Bik EM, Bernstein CN, et al. Diversity of the human intestinal microbial flora. Science. 2005;308(5728):1635-1638. [CrossRef]
  18. Arumugam M, Raes J, Pelletier E, et al. Enterotypes of the human gut microbiome [published correction appears in Nature. 2011 Jun 30;474(7353):666] [published correction appears in Nature. 2014 Feb 27;506(7489):516]. Nature. 2011;473(7346):174-180. [CrossRef]
  19. Mariat D, Firmesse O, Levenez F, et al. The Firmicutes/Bacteroidetes ratio of the human microbiota changes with age. BMC Microbiol. 2009;9:123. Published 2009 Jun 9. [CrossRef]
  20. Hollister EB, Gao C, Versalovic J. Compositional and functional features of the gastrointestinal microbiome and their effects on human health. Gastroenterology. 2014;146(6):1449-1458. [CrossRef]
  21. Anderson JW, Baird P, Davis RH Jr, et al. Health benefits of dietary fiber. Nutr Rev. 2009;67(4):188-205. [CrossRef]
  22. Louis P, Flint HJ. Formation of propionate and butyrate by the human colonic microbiota. Environ Microbiol. 2017;19(1):29-41. [CrossRef]
  23. Duncan SH, Belenguer A, Holtrop G, Johnstone AM, Flint HJ, Lobley GE. Reduced dietary intake of carbohydrates by obese subjects results in decreased concentrations of butyrate and butyrate-producing bacteria in feces. Appl Environ Microbiol. 2007;73(4):1073-1078. [CrossRef]
  24. Corrêa-Oliveira R, Fachi JL, Vieira A, Sato FT, Vinolo MA. Regulation of immune cell function by short-chain fatty acids. Clin Transl Immunology. 2016;5(4):e73. Published 2016 Apr 22. [CrossRef]
  25. Morrison DJ, Preston T. Formation of short chain fatty acids by the gut microbiota and their impact on human metabolism. Gut Microbes. 2016;7(3):189-200. [CrossRef]
  26. Chambers ES, Morrison DJ, Frost G. Control of appetite and energy intake by SCFA: what are the potential underlying mechanisms?. Proc Nutr Soc. 2015;74(3):328-336. [CrossRef]
  27. Wu W, Sun M, Chen F, et al. Microbiota metabolite short-chain fatty acid acetate promotes intestinal IgA response to microbiota which is mediated by GPR43. Mucosal Immunol. 2017;10(4):946-956. [CrossRef]
  28. LeBlanc JG, Milani C, de Giori GS, Sesma F, van Sinderen D, Ventura M. Bacteria as vitamin suppliers to their host: a gut microbiota perspective. Curr Opin Biotechnol. 2013;24(2):160-168. [CrossRef]
  29. Nicholson JK, Holmes E, Kinross J, et al. Host-gut microbiota metabolic interactions. Science. 2012;336(6086):1262-1267. https://doi.org/10.1126/science.1223813. [CrossRef]
  30. Marín L, Miguélez EM, Villar CJ, Lombó F. Bioavailability of dietary polyphenols and gut microbiota metabolism: antimicrobial properties. Biomed Res Int. 2015;2015:905215. [CrossRef]
  31. Cryan JF, O'Riordan KJ, Cowan CSM, et al. The Microbiota-Gut-Brain Axis. Physiol Rev. 2019;99(4):1877-2013. [CrossRef]
  32. Carabotti M, Scirocco A, Maselli MA, Severi C. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Ann Gastroenterol. 2015;28(2):203-209.
  33. Kurilshikov A, Wijmenga C, Fu J, Zhernakova A. Host Genetics and Gut Microbiome: Challenges and Perspectives. Trends Immunol. 2017;38(9):633-647. [CrossRef]
  34. Voreades N, Kozil A, Weir TL. Diet and the development of the human intestinal microbiome. Front Microbiol. 2014;5:494. Published 2014 Sep 22. [CrossRef]
  35. Koenig JE, Spor A, Scalfone N, et al. Succession of microbial consortia in the developing infant gut microbiome. Proc Natl Acad Sci U S A. 2011;108 Suppl 1(Suppl 1):4578-4585. [CrossRef]
  36. Iizumi T, Battaglia T, Ruiz V, Perez Perez GI. Gut Microbiome and Antibiotics. Arch Med Res. 2017;48(8):727-734. [CrossRef]
  37. Jandhyala SM, Talukdar R, Subramanyam C, Vuyyuru H, Sasikala M, Nageshwar Reddy D. Role of the normal gut microbiota. World J Gastroenterol. 2015;21(29):8787-8803. [CrossRef]
  38. Salazar N, Valdés-Varela L, González S, Gueimonde M, de Los Reyes-Gavilán CG. Nutrition and the gut microbiome in the elderly. Gut Microbes. 2017;8(2):82-97. [CrossRef]
  39. Pohl K, Moodley P, Dhanda AD. Alcohol's Impact on the Gut and Liver. Nutrients. 2021;13(9):3170. Published 2021 Sep 11. [CrossRef]
  40. Litwinowicz K, Choroszy M, Waszczuk E. Changes in the composition of the human intestinal microbiome in alcohol use disorder: a systematic review. Am J Drug Alcohol Abuse. 2020;46(1):4-12. [CrossRef]
  41. Huang C, Shi G. Smoking and microbiome in oral, airway, gut and some systemic diseases. J Transl Med. 2019;17(1):225. Published 2019 Jul 15. [CrossRef]
  42. Hughes RL. A Review of the Role of the Gut Microbiome in Personalized Sports Nutrition. Front Nutr. 2020;6:191. Published 2020 Jan 10. [CrossRef]
  43. Estaki M, Pither J, Baumeister P, et al. Cardiorespiratory fitness as a predictor of intestinal microbial diversity and distinct metagenomic functions. Microbiome. 2016;4(1):42. Published 2016 Aug 8. [CrossRef]
  44. Gomaa EZ. Human gut microbiota/microbiome in health and diseases: a review. Antonie Van Leeuwenhoek. 2020;113(12):2019-2040. [CrossRef]
  45. Mohr AE, Jäger R, Carpenter KC, et al. The athletic gut microbiota. J Int Soc Sports Nutr. 2020;17(1):24. Published 2020 May 12. [CrossRef]
  46. Syromyatnikov M, Nesterova E, Gladkikh M, Smirnova Y, Gryaznova M, Popov V. Characteristics of the Gut Bacterial Composition in People of Different Nationalities and Religions. Microorganisms. 2022;10(9):1866. Published 2022 Sep 18. [CrossRef]
  47. Costea PI, Hildebrand F, Arumugam M, et al. Enterotypes in the landscape of gut microbial community composition [published correction appears in Nat Microbiol. 2018 Mar;3(3):388. https://doi.org/10.1038/s41564-018-0114-x]. Nat Microbiol. 2018;3(1):8-16. [CrossRef]
  48. Adak A, Maity C, Ghosh K, Pati BR, Mondal KC. Dynamics of predominant microbiota in the human gastrointestinal tract and change in luminal enzymes and immunoglobulin profile during high-altitude adaptation. Folia Microbiol (Praha). 2013;58(6):523-528. [CrossRef]
  49. Chevalier C, Stojanović O, Colin DJ, et al. Gut Microbiota Orchestrates Energy Homeostasis during Cold. Cell. 2015;163(6):1360-1374. [CrossRef]
  50. Shreiner AB, Kao JY, Young VB. The gut microbiome in health and in disease. Curr Opin Gastroenterol. 2015;31(1):69-75. [CrossRef]
  51. Bhattarai Y, Muniz Pedrogo DA, Kashyap PC. Irritable bowel syndrome: a gut microbiota-related disorder?. Am J Physiol Gastrointest Liver Physiol. 2017;312(1):G52-G62. [CrossRef]
  52. Pittayanon R, Lau JT, Yuan Y, et al. Gut Microbiota in Patients With Irritable Bowel Syndrome-A Systematic Review. Gastroenterology. 2019;157(1):97-108. [CrossRef]
  53. Fabián O, Kamaradová K. Morphology of inflammatory bowel diseases (IBD). Morfologie zánětlivých střevních onemocnění (IBD). Cesk Patol. 2022;58(1):27-37.
  54. Lane ER, Zisman TL, Suskind DL. The microbiota in inflammatory bowel disease: current and therapeutic insights. J Inflamm Res. 2017;10:63-73. Published 2017 Jun 10. [CrossRef]
  55. Pittayanon R, Lau JT, Leontiadis GI, et al. Differences in Gut Microbiota in Patients With vs Without Inflammatory Bowel Diseases: A Systematic Review. Gastroenterology. 2020;158(4):930-946.e1. [CrossRef]
  56. Quaglio AEV, Grillo TG, De Oliveira ECS, Di Stasi LC, Sassaki LY. Gut microbiota, inflammatory bowel disease and colorectal cancer. World J Gastroenterol. 2022;28(30):4053-4060. [CrossRef]
  57. Liu BN, Liu XT, Liang ZH, Wang JH. Gut microbiota in obesity. World J Gastroenterol. 2021;27(25):3837-3850. [CrossRef]
  58. Walker AW, Hoyles L. Human microbiome myths and misconceptions. Nat Microbiol. 2023;8(8):1392-1396. [CrossRef]
  59. DeGruttola AK, Low D, Mizoguchi A, Mizoguchi E. Current Understanding of Dysbiosis in Disease in Human and Animal Models. Inflamm Bowel Dis. 2016;22(5):1137-1150. [CrossRef]
  60. Zhou H, Zhao X, Sun L, et al. Gut Microbiota Profile in Patients with Type 1 Diabetes Based on 16S rRNA Gene Sequencing: A Systematic Review. Dis Markers. 2020;2020:3936247. Published 2020 Aug 27. [CrossRef]
  61. Li Q, Chang Y, Zhang K, Chen H, Tao S, Zhang Z. Implication of the gut microbiome composition of type 2 diabetic patients from northern China. Sci Rep. 2020;10(1):5450. Published 2020 Mar 25. [CrossRef]
  62. Chen Y, Zhou J, Wang L. Role and Mechanism of Gut Microbiota in Human Disease. Front Cell Infect Microbiol. 2021;11:625913. Published 2021 Mar 17. [CrossRef]
  63. Qin J, Li Y, Cai Z, et al. A metagenome-wide association study of gut microbiota in type 2 diabetes. Nature. 2012;490(7418):55-60. [CrossRef]
  64. Westfall S, Lomis N, Kahouli I, Dia SY, Singh SP, Prakash S. Microbiome, probiotics and neurodegenerative diseases: deciphering the gut brain axis. Cell Mol Life Sci. 2017;74(20):3769-3787. [CrossRef]
  65. Megur A, Baltriukienė D, Bukelskienė V, Burokas A. The Microbiota-Gut-Brain Axis and Alzheimer's Disease: Neuroinflammation Is to Blame?. Nutrients. 2020;13(1):37. Published 2020 Dec 24. [CrossRef]
  66. Simpson CA, Diaz-Arteche C, Eliby D, Schwartz OS, Simmons JG, Cowan CSM. The gut microbiota in anxiety and depression - A systematic review. Clin Psychol Rev. 2021;83:101943. [CrossRef]
  67. Fattorusso A, Di Genova L, Dell'Isola GB, Mencaroni E, Esposito S. Autism Spectrum Disorders and the Gut Microbiota. Nutrients. 2019;11(3):521. Published 2019 Feb 28. [CrossRef]
  68. Witkowski M, Weeks TL, Hazen SL. Gut Microbiota and Cardiovascular Disease. Circ Res. 2020;127(4):553-570. [CrossRef]
  69. Belvoncikova P, Maronek M, Gardlik R. Gut Dysbiosis and Fecal Microbiota Transplantation in Autoimmune Diseases. Int J Mol Sci. 2022;23(18):10729. Published 2022 Sep 14. [CrossRef]
  70. Ostfeld RJ. Definition of a plant-based diet and overview of this special issue. J Geriatr Cardiol. 2017;14(5):315. [CrossRef]
  71. Hargreaves SM, Raposo A, Saraiva A, Zandonadi RP. Vegetarian Diet: An Overview through the Perspective of Quality of Life Domains. Int J Environ Res Public Health. 2021;18(8):4067. Published 2021 Apr 12. [CrossRef]
  72. Merra G, Noce A, Marrone G, et al. Influence of Mediterranean Diet on Human Gut Microbiota. Nutrients. 2020;13(1):7. Published 2020 Dec 22. [CrossRef]
  73. Kimble R, Gouinguenet P, Ashor A, et al. Effects of a mediterranean diet on the gut microbiota and microbial metabolites: A systematic review of randomized controlled trials and observational studies. Crit Rev Food Sci Nutr. 2023;63(27):8698-8719. [CrossRef]
  74. Varlamov O. Western-style diet, sex steroids and metabolism. Biochim Biophys Acta Mol Basis Dis. 2017;1863(5):1147-1155. [CrossRef]
  75. Malesza IJ, Malesza M, Walkowiak J, et al. High-Fat, Western-Style Diet, Systemic Inflammation, and Gut Microbiota: A Narrative Review. Cells. 2021;10(11):3164. Published 2021 Nov 14. [CrossRef]
  76. Sidhu SRK, Kok CW, Kunasegaran T, Ramadas A. Effect of Plant-Based Diets on Gut Microbiota: A Systematic Review of Interventional Studies. Nutrients. 2023;15(6):1510. Published 2023 Mar 21. [CrossRef]
  77. Beam A, Clinger E, Hao L. Effect of Diet and Dietary Components on the Composition of the Gut Microbiota. Nutrients. 2021;13(8):2795. Published 2021 Aug 15. [CrossRef]
  78. Trefflich I, Jabakhanji A, Menzel J, et al. Is a vegan or a vegetarian diet associated with the microbiota composition in the gut? Results of a new cross-sectional study and systematic review. Crit Rev Food Sci Nutr. 2020;60(17):2990-3004. [CrossRef]
  79. Losno EA, Sieferle K, Perez-Cueto FJA, Ritz C. Vegan Diet and the Gut Microbiota Composition in Healthy Adults. Nutrients. 2021;13(7):2402. Published 2021 Jul 13. [CrossRef]
  80. Luisi MLE, Lucarini L, Biffi B, et al. Effect of Mediterranean Diet Enriched in High Quality Extra Virgin Olive Oil on Oxidative Stress, Inflammation and Gut Microbiota in Obese and Normal Weight Adult Subjects. Front Pharmacol. 2019;10:1366. Published 2019 Nov 15. [CrossRef]
  81. Costantini L, Molinari R, Farinon B, Merendino N. Impact of Omega-3 Fatty Acids on the Gut Microbiota. Int J Mol Sci. 2017;18(12):2645. Published 2017 Dec 7. [CrossRef]
  82. De Filippis F, Pellegrini N, Vannini L, et al. High-level adherence to a Mediterranean diet beneficially impacts the gut microbiota and associated metabolome. Gut. 2016;65(11):1812-1821. [CrossRef]
  83. Martini D. Health Benefits of Mediterranean Diet. Nutrients. 2019;11(8):1802. Published 2019 Aug 5. [CrossRef]
  84. So D, Whelan K, Rossi M, et al. Dietary fiber intervention on gut microbiota composition in healthy adults: a systematic review and meta-analysis. Am J Clin Nutr. 2018;107(6):965-983. [CrossRef]
  85. Barber TM, Kabisch S, Pfeiffer AFH, Weickert MO. The Effects of the Mediterranean Diet on Health and Gut Microbiota. Nutrients. 2023;15(9):2150. Published 2023 Apr 29. [CrossRef]
  86. Zinöcker MK, Lindseth IA. The Western Diet-Microbiome-Host Interaction and Its Role in Metabolic Disease. Nutrients. 2018;10(3):365. Published 2018 Mar 17. [CrossRef]
  87. Wolters M, Ahrens J, Romaní-Pérez M, et al. Dietary fat, the gut microbiota, and metabolic health - A systematic review conducted within the MyNewGut project. Clin Nutr. 2019;38(6):2504-2520. [CrossRef]
  88. Miranda PM, De Palma G, Serkis V, et al. High salt diet exacerbates colitis in mice by decreasing Lactobacillus levels and butyrate production. Microbiome. 2018;6(1):57. Published 2018 Mar 22. [CrossRef]
  89. Abu-Ghazaleh N, Chua WJ, Gopalan V. Intestinal microbiota and its association with colon cancer and red/processed meat consumption. J Gastroenterol Hepatol. 2021;36(1):75-88. [CrossRef]
  90. Ramne S, Brunkwall L, Ericson U, et al. Gut microbiota composition in relation to intake of added sugar, sugar-sweetened beverages and artificially sweetened beverages in the Malmö Offspring Study. Eur J Nutr. 2021;60(4):2087-2097. [CrossRef]
Table 1. Effect of dietary types on gut microbiota composition.
Table 1. Effect of dietary types on gut microbiota composition.
Dietary type Reference Studies Sample Main findings
Plant-based Sidhu et al (2023) [76] 12 interventional studies 583 participants, 21-61 years old, men and women healthy, obese, with rheumatoid arthritis and
cardiovascular risk		 ↑Ruminococcaceae and
↓ Bacteroidaceae in individuals following plant-based diet,
Coprococcus and Faecalibacterium increased in vegans and decreased in vegetarians
Plant-based Trefflich et al (2020) [78] 16 cross-sectional studies 1229 participants, 498 omnivores, 389 vegetarians and 342 vegans, 18-72 years old (except for 1 study), men and women ↑ Bacteroidetes,
↓ Proteobacteria and
↑ Verrucomicrobia in vegans compared to omnivores, Firmicutes levels were similar,
↑ Actinobacteria in vegetarians
Mediterranean Kimble et al (2023) [73] 34 studies in total, 17 randomized control trials, 17 observational (3 prospective and 14 cross-sectional
 4526 participants 22- 95 years old, majority healthy, others with a medical condition ↑ Bacteroidetes and
↓ Firmicutes in individuals, following Mediterranean diet, also
↑ Faecalibacterium prausnitzii
Western Wolters et al (2019) [87] 15 studies in total, 9 cross-sectional observational studies, 6 randomized control trials From 9 to 531 participants (cross-sectional observational studies), from 20 to 88 participants (randomized control trials), mean age 8.1- 63.3 years old,
10 studies included men and women, 2 only men and 3 only women		 ↓ of total bacteria in individuals following diet high in monounsaturated fatty acids (MUFA),
↑ Firmicutes and
↓ Bacteroidetes,
increase in Prevotella, Enterobacteriaceae, Parabacteroides and Turicibacter populations
Table 2. Firmicutes/Bacteroidetes ratio, SCFA and TMAO production change with different dietary types.
Table 2. Firmicutes/Bacteroidetes ratio, SCFA and TMAO production change with different dietary types.
Plant-based diet Mediterranean diet Western diet
Firmicutes/Bacteroidetes ratio ↓ (Trefflich et al., 2020) [78] ↓ (Kimble et al., 2023) [73] ↑ (Wolters et al., 2019) [87] (Ramne et al., 2021) [90]
SCFA production ↑ (Sidhu et al., 2023) [76] ↑ (Merra et al., 2020) [72] ↓ (Miranda et al., 2018) [88]
TMAO production ↓ (Beam et al., 2021) [77] ↓ (De Filippis et al., 2016) [82] ↑ (Sidhu et al., 2023) [76]
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