New Research Shows Infant Gut Bacteria Has Its Own Circadian Rhythm

Updated May 8, 2024

Fact-Checked

The Sleep Foundation editorial team is dedicated to providing content that meets the highest standards for accuracy and objectivity. Our editors and medical experts rigorously evaluate every article and guide to ensure the information is factual, up-to-date, and free of bias.

The Sleep Foundation fact-checking guidelines are as follows:

We only cite reputable sources when researching our guides and articles. These include peer-reviewed journals, government reports, academic and medical associations, and interviews with credentialed medical experts and practitioners.
All scientific data and information must be backed up by at least one reputable source. Each guide and article includes a comprehensive bibliography with full citations and links to the original sources.
Some guides and articles feature links to other relevant Sleep Foundation pages. These internal links are intended to improve ease of navigation across the site, and are never used as original sources for scientific data or information.
A member of our medical expert team provides a final review of the content and sources cited for every guide, article, and product review concerning medical- and health-related topics. Inaccurate or unverifiable information will be removed prior to publication.
Plagiarism is never tolerated. Writers and editors caught stealing content or improperly citing sources are immediately terminated, and we will work to rectify the situation with the original publisher(s)
Although Sleep Foundation maintains affiliate partnerships with brands and e-commerce portals, these relationships never have any bearing on our product reviews or recommendations. Read our full Advertising Disclosure for more information.

In recent years, gut health has become a trending topic that’s at the center of a nearly $52 billion digestive health industry. Even by itself, the gut microbiome market is worth nearly $95 million and is expected to grow significantly.

While there are numerous supplements marketed toward improved gut health, the bacteria in your gut, also called the gut microbiome, start to develop naturally in infancy. A new study from researchers in Germany suggests that some of these bacteria actually operate on a circadian rhythm, Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source or sleep-wake cycle, that can affect infants’ long-term and short-term health, along with the babies’ own circadian rhythms.

When a baby is born, their gut is sterile, Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source or close to it. The birthing process, aging, and food intake all help the development of a baby’s gut microbiome. The healthy bacteria present in the gut aid in the development of the immune system, the central nervous system, and digestion. Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source

The researchers performed a randomized trial with infants who were breastfed and others who consumed formula, comparing differences in gut microbiomes between the two. They found that while there were variations in bacteria between the two populations, age affected the development of gut bacteria rhythms more than diet.

During the first year of life, an infant gradually develops a sleep-wake cycle. Trusted Source National Library of Medicine, Biotech Information The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. View Source This partly explains why newborns have such irregular sleep patterns at first but slowly adapt to sleeping through the night as they grow.

Interestingly, the new study showed that particular bacteria within infants’ gut microbiomes have a circadian rhythm, becoming active and inactive with environmental factors like light exposure and feeding times. The researchers also noted that the circadian rhythms are bidirectional — the body’s internal clock helps regulate the sleep-wake cycle of the gut microbiome, and vice versa.

The research team believes that the circadian nature of infants’ gut bacteria could affect disease development. Because there appears to be communication between an infant’s sleep-wake cycle and their gut bacteria’s sleep-wake cycle, outside factors like lack of natural light exposure or irregular feedings could hinder gut microbiome development and affect overall health.

The study acknowledged certain limitations, including a small sample size of 210 infants and restricted timing for stool sample collections. Additional research could help bolster the study’s findings and further explore the link between a person’s circadian rhythm and the 24-hour cycles present within gut bacteria.

Got a hot tip? Pitch us your story idea, share your expertise with SleepFoundation.org, or let us know about your sleep experiences right here.

Written By

Cassandra Burns, Contributing Writer

Cassandra is a professional writer who specializes in search engine optimization. Cassandra writes about a wide variety of sleep products, but, as a side sleeper, she particularly enjoys writing about pressure relief. She has lived in many places across the country and recently returned to her native Upstate New York where she enjoys mountain biking, whitewater rafting, and the never-ending challenge of trying to tire out her dog.

Learn more about our Editorial Team

References
6 Sources

Grand View Research, Inc. (n.d.). Digestive health products market size, share & trend analysis report by product (dairy products, bakery & cereals, non-alcoholic beverages, supplements, others), by ingredient, by region, and segment forecasts, 2024 – 2030., Retrieved May 2, 2024, from
https://www.grandviewresearch.com/industry-analysis/digestive-health-products-market
Grand View Research, Inc. (n.d.). Microbiome therapeutics market size, share & trends analysis report by type (FMT, microbiome drugs), by application (C. difficile, Crohn’s disease, inflammatory bowel disease, diabetes), by region, and segment forecasts, 2023 – 2030., Retrieved May 2, 2024, from
https://www.grandviewresearch.com/industry-analysis/microbiome-therapeutics-market
Heppner, N., Reitmeier, S., Heddes, M., Merino, M., Schwartz, L., Dietrich, A., List, M., Gigl, M., Meng, C., Van Der Veen, D. R., Schirmer, M., Kleigrewe, K., Omer, H., Kiessling, S., & Haller, D. (2024). Diurnal rhythmicity of infant fecal microbiota and metabolites: A randomized controlled interventional trial with infant formula. Cell Host & Microbe, 32(4), 573–587.
https://pubmed.ncbi.nlm.nih.gov/38569545/
‌Bull, M. J., & Plummer, N. T. (2014). Part 1: The human gut microbiome in health and disease. Integrative Medicine, 13(6), 17–22.
https://pubmed.ncbi.nlm.nih.gov/26770121/
Yao, Y., Cai, X., Ye, Y., Wang, F., Chen, F., & Zheng, C. (2021). The role of microbiota in infant health: From early life to adulthood. Frontiers in Immunology, 12.
https://pubmed.ncbi.nlm.nih.gov/34691021/
Wong, S. D., Wright, K. P., Spencer, R. L., Vetter, C., Hicks, L. M., Jenni, O., & LeBourgeois, M. K. (2022). Development of the circadian system in early life: Maternal and environmental factors. Journal of Physiological Anthropology, 41(1).
https://pubmed.ncbi.nlm.nih.gov/35578354/