SIBO is a pathology of the small intestine and may predispose individuals to a range of nutritional deficiencies. Very little is known whether specific subtypes of SIBO, such as hydrogen-dominant (H+), methane-dominant (M+), or hydrogen/methane –dominant (H+/M+), impact nutritional status and dietary intake in SIBO patients. The aim of this study was to investigate possible correlations between biochemical parameters, dietary nutrient intake, and distinct SIBO subtypes. This observational study included 67 patients who were newly diagnosed with SIBO. Biochemical parameters and diet were studied utilizing laboratory tests and food records, respectively. The H+/M+ group was associated with low serum vitamin D (p<0.001), low serum ferritin (p=0.001) and low fiber intake (p=0.001). The M+ group was correlated with high serum folic acid (p=0.002) and low intakes of fiber (p=0.001) and lactose (p=0.002). The H+ group was associated with low lactose intake (p=0.027). These results suggest that the subtype of SIBO may have varying effects on dietary intake, leading to a range of deficiencies in the body. Conversely, specific dietary patterns may predispose to the development of a SIBO subtype. The assessment of nutritional status and diet, along with diagnosis of SIBO substype, are believed to be key components of SIBO therapy.