News Release

Bad habits in childhood may lead to an 'unhealthy' balance of gut bacteria

Peer-Reviewed Publication

European Society for Paediatric Endocrinology

Preliminary data suggests that a child’s sleeping, eating and fitness habits can influence the balance of bacteria found in their gut as teenagers, according to research presented today at the 57th Annual European Society for Paediatric Endocrinology Meeting. These findings indicate that maintaining healthy lifestyle habits during childhood may promote a healthy balance of gut bacteria later in life, which in turn may contribute to lowering the risks of developing serious long-term conditions such as diabetes and cardiovascular disease.

The gut is home to a highly complex microbial community consisting of trillions of diverse tiny microorganisms, collectively called the microbiota. In a healthy state, these microorganisms work in harmony with the body to help digest food, generate and use energy and promote normal organ and immune function. However, changes in the balance of the gut microbiota have been linked to an increased risk of insulin resistance and type-2 diabetes, high cholesterol levels and cardiovascular disease. Emerging research also suggests a link to obesity, with differences in microbiota diversity and composition noted between lean and obese people. Diet has been shown to influence gut microbiota diversity in adults but little is known about the impact of other lifestyle factors, as well as diet, on the microbiota during childhood.

In this study by Dr Melanie Henderson and colleagues at CHU Sainte-Justine in Montreal, lifestyle factors of 22 healthy children, with at least one obese parent, were monitored over 8 years. When the children reached 15-17 years, the composition and diversity of their gut microbiota was measured from stool samples. The study findings suggested that certain lifestyle factors during childhood may influence the composition and diversity of gut microbiota in late adolescence. Teenagers, who had higher fitness levels, ate less fat and more carbohydrate, and had adequate sleep during their childhood, had a healthier and more diverse composition of gut microbiota.

"These preliminary findings reveal that not just diet, but other lifestyle factors including low fitness levels and poor sleep behavior are likely involved in the development of an 'unhealthier' gut microbiome, which may increase the risk of children developing more serious conditions in later life," commented Dr Henderson.

Whilst the findings are preliminary, with only a small number of children studied, they suggest that mechanisms related to lifestyle habits may affect the growth of gut microbiota, which Dr Henderson intends to examine in the next phase of her study.

Dr Henderson states, "The results of this study certainly suggest that lifestyle changes during childhood may help to favour a healthy intestinal microbiota, which may in turn lower the risk of developing cardiometabolic diseases such as diabetes, however further research is needed to confirm these findings in a larger number of children."



More than a gut feeling: preliminary evidence supporting a role for lifestyle habits in shaping the intestinal microbiota in childhood and adolescence
Mélanie Henderson1,2, Andraea Van Hulst1,3, Gabrielle Simoneau1,4, Tracie A. Barnett1,5, Vicky Drapeau6, Marie-Ève Mathieu7, Belinda Nicolau8, Thibaut Varin9, André Marette9

1 Centre de Recherche du CHU Sainte Justine, Montréal, Canada. 2 Division of Endocrinology, Department of Pediatrics, CHU Sainte-Justine and Université de Montréal, Montréal, Canada. 3 Ingram School of Nursing, McGill University, Montréal, Canada. 4 Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Canada. 5 Epidemiology and Biostatistics Unit, Centre INRS - Institut Armand-Frappier, Laval, Canada. 6 Department of Physical Education, Université Laval, Québec, Canada. 7 Department of Kinesiology, Université de Montréal, Montréal, Canada. 8 Department of Dentistry, McGill University, Montréal, Canada. 9 Department of Medicine, IUCPQ and INAF, Université Laval, Québec, Canada

Background: Dietary intake has been shown to influence the composition and diversity of the gut microbiota in adults, however its impact in childhood and adolescence remains uncertain. Moreover, the impact of other lifestyle behaviors such as physical activity, sedentary behaviors, sleep and fitness on the gut microbiota has rarely been investigated.

Objective: To explore the correlations between intestinal microbiota composition and measures of diversity among 15-17 year-old adolescents with a family history of obesity and

  1. lifestyle habits at 15-17 years;
  2. lifestyle habits in earlier childhood.

Methods: Data stem from the QUALITY cohort, a prospective cohort study of 630 children with a parental history of obesity. Lifestyle habits were assessed at 8-10 yrs, 10-12 yrs and 15-17 yrs, including: physical activity by 7-day accelerometry, self-reported screen time, dietary intake (at 8-10 and 15-17 yrs only) by 3 non-consecutive 24h dietary recalls, and self-reported sleep duration. Fitness was measured by VO2peak. 16S-rRNA based microbial profiling of stool samples obtained from 22 participants at 15-17 yrs (14 normal weight, 6 overweight and 2 obese) were performed to determine composition and diversity of the gut microbiota. Measures of diversity include Shannon, Simpson, Chao1 and Observed OTU indices. Pearson's correlations assessed associations between diversity indices and lifestyle habits.

Results: Fitness at 15-17 yrs was positively correlated with measures of diversity (r = 0.33-0.41 across all indices). More importantly, statistically significant positive correlations were noted between fitness at 10-12 yrs and greater microbiotal diversity 5 years later (Shannon r=0.70, p=0.001; Simpson r=0.51, p=0.03; Obs OTU r=0.50, p=0.036). Physical activity and screen time were not associated with microbiota diversity. Both total dietary fat intake and saturated fat intake at 15-17 yrs were negatively correlated with the Simpson index (r=-0.50, p=0.019 and r=-0.43, p=0.046, respectively). Similar, not quite statistically significant, negative correlations between total and saturated fat consumption at 8-10 yrs and measures of diversity at 15-17 yrs were also noted. At both 8-10 yrs and 15-17 yrs, percent carbohydrate intake was positively correlated with the Simpson index (r= 0.43, p=0.049 and r= 0.49, p=0.021, respectively). Finally, sleep duration at 10-12 yrs tended to positively correlate with indices of diversity at 15-17 yrs, the strongest correlation being with the Shannon index (r= 0.39, p=0.08).

Conclusions: These preliminary findings from a small sample of children followed over 8 years suggest that microbiome diversity in late adolescence may be modulated by lifestyle habits, even in earlier childhood.

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