Gut microbiota link dietary fiber intake and short-chain fatty acid metabolism with eating behaviour
AbstractObjectivesThe gut microbiome modulates human brain function and eating behavior through multiple factors, including short-chain fatty acid (SCFA) signaling. We aimed to determine which bacterial genera relate to eating behavior, diet and SCFA metabolites in overweight adults. In addition, we tested whether eating-related microbiota predict treatment success in patients after bariatric surgery.DesignAnthropometrics, eating behaviour measures and 16S-rRNA-derived microbiota abundance were correlated in young overweight adults (n=27 (9F), 21-36 years, BMI 25-31 kg/m2), and in patients two years after Roux-en-Y gastric bypass (n=23 (16F), 41-70 years, BMI 25-62 kg/m2) compared to matched overweight and obese controls (n=17 (11F), 26-69 years, BMI 25-48 kg/m2). Dietary fiber intake was assessed and SCFA were measured in feces and blood using mass spectrometry in young adults.ResultsIn the young adults, 7 bacteria genera, i.e. Alistipes, Blautia, Clostridiales cluster XVIII, Gemmiger, Roseburia, Ruminococcus and Streptococcus, correlated with healthier eating behavior, while 5 genera, i.e. Clostridiales cluster IV and XIVb, Collinsella, Fusicatenibacter and Parabacteroides, correlated with unhealthier eating (all |r| > 0.4, FDR-corrected p < 0.05). Some of these genera including Parabacteroides related to fiber intake and SCFA metabolites, and to weight status and treatment response in obese patients.ConclusionSpecific bacterial genera, particularly Parabacteroides, were reliably associated with weight status and eating behavior in two independent well-characterized cross-sectional samples. Together, these findings indicate two groups of presumably beneficial and unfavourable genera that relate to eating behaviour and weight status, and indicate that dietary fiber and SCFA metabolism may modify these relationships.Significance of this studyWhat is already known about this subject?-The gut microbiome may modulate brain function and eating behavior through production of short-chain fatty acids (SCFA) from dietary fiber.What are the new findings?-This cross-sectional exploratory study finds that the abundance of specific groups of bacterial genera, including Parabacteroides, correlate with eating behavior, diet, SCFA as well as weight status and obesity treatment success in two independent well-characterized samples.How might it impact on clinical practice in the foreseeable future?-These findings might help to develop novel hypotheses how to prevent and treat unhealthy food craving through microbiotal modulation of the gut-brain axis.