Rationale: Intestinal microbiota plays a significant role in the human body. A range of negative factors may lead to dysbiosis, which results in many diseases (e.g. cancer) and metabolic disorders. It has been shown that people with a body mass index (BMI) of ≥25 kg/m² present diminished microbial diversity. Additional negative factors such as stress, the use of non-steroidal anti-inflammatory drugs (NSAID) and proton pomp inhibitors (PPI) may result in greater dysbiosis compared to people with normal body mass. The aim of the study was to compare the incidence of negative factors affecting the intestinal microbiota in people with excessive body mass vs. people with normal body mass.

Methods: The study involved volunteers aged 18-65 years: 582 people with normal BMI (18.5 - 24.99 kg/m²) and 538 people with BMI ≥25 kg/m². The study was conducted using the author's survey by the Computer-Assisted Web Interviewing method. The survey included the questions on sociodemographic features, level of physical activity, frequency of smoking, and stress. Frequency of NSAID and PPI use was also investigated. BMI was used to assess nutritional status. For statistics the Fisher test was implemented. P-value <0.05 was considered significant.

Results: Women predominated in the study (p<0.0001). People with normal BMI had a significantly higher level of physical activity (p<0.0001) and smoked less (p=0.0356). People with excessive body mass were less likely to report illness (p=0.0004), but more often they took PPI (p=0.0337).

Conclusions: People with BMI ≥ 25 kg/m² present more factors which may result in dysbiosis and lead to dysbiosis-related health problems in future compared to people with normal BMI.