They found that diet and physical activity levels were similar between groups. Compared to lean participants, those who were overweight/obese had higher SCFAs overall: higher fecal acetate, propionate, butyrate, and valerate. Researchers observed no significant differences in F:B ratio between the groups, but among all participants, higher Bacteroides/Prevotella counts were associated with lower fecal SCFAs. F:B ratio correlated with higher fecal SCFAs.
The results suggest that SCFAs and F:B ratio vary together and may be interrelated. Colonic fermentation patterns may be altered — but not necessarily by diet — leading to different SCFA concentrations in fecal samples of lean and overweight/obese humans.
This study is limited by the lack of mechanistic insight into these associations and its reliance on self-reported data about diet and physical activity.