Time of day and eating behaviors are associated with the composition and function of the human gastrointestinal microbiota

Abstract

Preclinical research has shown that the gastrointestinal microbiota exhibits circadian rhythms and that the timing of food consumption can affect the composition and function of gut microbes. However, there is a dearth of knowledge on these relations in humans. We aimed to determine whether human gastrointestinal microbes and bacterial metabolites were associated with time of day or behavioral factors, including eating frequency, percentage of energy consumed early in the day, and overnight-fast duration. We analyzed 77 fecal samples collected from 28 healthy men and women. Fecal DNA was extracted and sequenced to determine the relative abundances of bacterial operational taxonomic units (OTUs). Gas chromatography-mass spectroscopy was used to assess short-chain fatty acid concentrations. Eating frequency, percentage of energy consumed before 1400, and overnight-fast duration were determined from dietary records. Data were analyzed by linear mixed models or generalized linear mixed models, which controlled for fiber intake, sex, age, body mass index, and repeated sampling within each participant. Each OTU and metabolite were tested as the outcome in a separate model. Acetate, propionate, and butyrate concentrations decreased throughout the day ( = 0.006, 0.04, and 0.002, respectively). Thirty-five percent of bacterial OTUs were associated with time. In addition, relations were observed between gut microbes and eating behaviors, including eating frequency, early energy consumption, and overnight-fast duration. These results indicate that the human gastrointestinal microbiota composition and function vary throughout the day, which may be related to the circadian biology of the human body, the microbial community itself, or human eating behaviors. Behavioral factors, including timing of eating and overnight-fast duration, were also predictive of bacterial abundances. Longitudinal intervention studies are needed to determine causality of these biological and behavioral relations. This trial was registered at clinicaltrials.gov as NCT01925560.

Timing of food intake impacts daily rhythms of human salivary microbiota: a randomized, crossover study

“…Therefore, this observation in the gut microbiota under LE conditions may suggest a potential proinflammatory profile and a higher risk of intestinal inflammatory‐related diseases with LE in fecal microbiota. Along those lines, a recent observational study has reported significant associations between the relative abundance of several gut bacterial families and the distribution of energy intake before or after 1400 h (25). Nevertheless, further food timing interventional studies in obese and diabetic subjects are needed to confirm these results.…”

“…The impact of timing of food intake on microbiota in humans has not been investigated. However, studies in rodents on feeding patterns (23), in equines on feeding frequency (24) and in humans on daily energy intake distribution and gut microbial abundances (25) have provided compelling evidence to support the hypothesis that several aspects related to the time of eating can affect microbiota and could be one of the mechanisms for late‐eating—induced metabolic dysfunction.…”

Microbiota modulation by eating patterns and diet composition: impact on food intake

“…TRF on weekdays has been shown to restrict weight gain in HFD-fed juvenile male rats (between 5 and 13 wk of age) independently of caloric intake (47). TRF is associated with increased production of SCFAs, specifically acetate, propionate, and butyrate (34). TRF also restores normal circadian cycling within the microbiota composition, characterized by an increase in Firmicutes abundance during the day and a decrease during the night (67).…”

At the Intersection of Microbiota and Circadian Clock: Are Sexual Dimorphism and Growth Hormones the Missing Link to Pathology?

“…In contrast to studies in mouse models, clinical studies investigating diurnal fluctuations in gut microbiota remain scarce . In particular, these observations are from small subject cohorts and rely only on limited time points.…”