Energy Metabolism and Gut Microbiome Interactions

Energy metabolism in humans and other mammals arises from the conversion of ingested nutrients into cellular energy, a process intimately modulated by the diverse microbial communities in the gastrointestinal tract. The gut microbiome influences host caloric harvest through fermentation of dietary substrates, yielding metabolites such as short-chain fatty acids that serve both as energy sources and signalling molecules. Variation in microbial composition and function can alter the host’s capacity to extract energy, regulate appetite, modulate enteroendocrine signalling and affect energy expenditure. Emerging evidence highlights the relevance of microbial biomass, metabolite profiles and ecosystem dynamics—such as enterotype classifications and keystone species—in shaping individual differences in metabolizable energy. Dietary patterns, circadian rhythms and host genetics further interact with microbial populations to influence energy homeostasis. Disruption of these interactions has been implicated in obesity, metabolic syndrome and disordered energy balance. Contemporary research employs controlled clinical trials, germ-free animal models and multi-omics approaches to elucidate causal mechanisms, with the ultimate aim of informing personalised nutritional strategies and interventions that target the microbiome to modulate energy metabolism and improve metabolic health on a global scale.

Research from Nature Portfolio

Recent studies in controlled clinical settings have quantified the specific contributions of the gut microbiome to human energy balance. In a well-controlled feeding study, a diet designed to enhance microbiome substrate availability led to increased microbial fermentation and biomass, resulting in higher daily energy losses in faeces and a consequent reduction in host metabolizable energy without altering energy expenditure or appetite. Comprehensive measurement of energy intake, output and enteroendocrine markers underpins the complex interplay between diet, microbial community structure and host energy homeostasis, revealing substantial interindividual variability that is partly explained by microbial fermentation products.

Energy Metabolism and Gut Microbiome Interactions publication trend

The graph below shows the total number of articles in energy metabolism and gut microbiome interactions across all publications each year (not limited to Nature Index journals).

Technical terms

Metabolizable energy: The fraction of ingested energy available to the host after accounting for faecal and urinary losses.

Short-chain fatty acids (SCFAs): Microbial fermentation products (such as acetate, propionate and butyrate) that serve as energy sources and signalling molecules.

Enterotype: A classification of gut microbial community composition based on dominant taxa that reflects ecosystem structure.

Keystone species: A microbial taxon with a disproportionate influence on community function and host physiology despite low relative abundance.

Microbial biomass: The total mass of microbial cells within the gut, which contributes to energy assimilation and nutrient cycling.

References

1. Host-diet-gut microbiome interactions influence human energy balance: a randomized clinical trial. Nature Communications (2023).
2. Exploring the Influence of Gut Microbiome on Energy Metabolism in Humans. Advances in Nutrition (2023).
3. Stool energy density is positively correlated to intestinal transit time and related to microbial enterotypes. Microbiome (2022).
4. The keystone gut species Christensenella minuta boosts gut microbial biomass and voluntary physical activity in mice. mBio (2023).