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Does Maternal Obesity Affect the Gut Microbiome of the Offspring?

Yesterday, I blogged about the Maternal Resource Hypothesis, proposed by Edward Archer, as a driver of childhood obesity. Today’s post is about another interesting finding by Jeffrey Galley and colleagues from Ohio State University, published in PLOS one, suggesting that maternal obesity may be associated with differences in the gut microbiome in children in early life. The researchers compared the gut bugs from fecal samples from children 18–27 months of age (n = 77) born to obese or non-obese mothers. At least in women of higher socioeconomic status, offspring of obese mothers showed significant differences in their gut bacteriome from those of non-obese mothers in a manner that has been previously linked to differences in weight and diet (differences were noted in the abundances of Faecalibacterium spp., Eubacterium spp., Oscillibacter spp., and Blautia spp). While these findings were limited to women of higher socioeconomic status, the authors do not have a ready explanation for these findings. Their best guess is that perhaps the etiology of obesity may differ between women of higher and lower socioeconomic status and it may well be that the extent to which maternal obesity confers measureable changes to the gut microbiome of offspring may differ based on the etiology of maternal obesity. It is unlikely that dietary differences explain these findings: “In our sample, we found no differences in the children from obese and non-obese mothers in terms of breastfeeding behavior, age at which solid foods were introduced, or the current frequency of consumption of meat, vegetables, and cereals/grains regardless of maternal SES. This suggests that diet did not explain the observed differences in the children’s gut microbiome related to maternal obesity and SES.” Indeed, the authors are quick to point out that further research is needed to better understand the relevance of the observed differences in gut microbiome composition for weight trajectory over the life course of the offspring: “The potential role of the gut microbiome in this intergenerational transmission of obesity risk warrants further attention. In particular, the stability of such effects into later childhood and adolescence, the clinical relevance of abundances of specific bacteria in conferring risk for obesity, and the ultimate impact of early life microbial profiles on long-term weight trajectory remains to be explicated.” Nevertheless, these findings are intriguing in that they suggest a link between maternal obesity and the possible transmission of obesogenic microbes to their offspring. @DrSharma Vancouver, BC Galley JD, Bailey M, Kamp Dush C, Schoppe-Sullivan S, & Christian LM (2014). Maternal… Read More »

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Prebiotic Fibre Alters Mother Milk and Offspring Gut Bacteria in Rats

With all the attention to the role of gut microbiota and the ongoing debate as to the role of breast feeding in obesity prevention, a study by Raylene Reimer and colleagues from the University of Calgary adds an interesting spin. Their study, now published in OBESITY shows that feeding female rat a diet high in prebiotic fibre (21.6% wt/wt) throughout pregnancy and lactation, compared to a control or high-protien (40% wt/wt) diet, results in a lower oligosaccharide content of the milk with a higher content of bifidobacteria in the offspring. Although this did not lead to any marked differences in body composition or other metabolic parameters, the study proves the point that (at least in rats) maternal diet can affect the composition of gut bacteria in the offspring (which may or may not have metabolic benefits). There is no reason to believe that in humans maternal nutrition may well impart a similar influence via breast feeding on the microbiota of infants. This certainly sounds like a promising field for future research. @DrSharma Edmonton, AB Hallam MC, Barile D, Meyrand M, German JB, & Reimer RA (2014). Maternal high protein or prebiotic fiber diets affect maternal milk composition and gut microbiota in rat dams and their offspring. Obesity (Silver Spring, Md.) PMID: 25056822 .

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Infant Antibiotic Exposure and Obesity Risk

With all the interest in the role of the gut bacteriome in the development of obesity, it was only a matter of time before someone examined the relationship between antibiotic use and obesity risk. This is exactly what Anita Kozyrskyj and colleagues from the University of Alberta, Edmonton, Canada, explored in a paper now published in the International Journal of Obesity. For their study they linked rovincial healthcare records to clinical and survey data from a Canadian longitudinal birth cohort study, whereby antibiotic exposure during the first year of life was documented from prescription records. Overweight and central adiposity were determined from anthropometric measurements at ages 9 (n=616) and 12 (n=431) years. According to this analysis, infants receiving antibiotics in the first year of life were about twice as likely to be overweight later in childhood compared to those who were unexposed. However, after adjustment for birth weight, breastfeeding, maternal overweight and other potential confounders, this association persisted in boys but not in girls. The reason for this discrepancy is not clear. Although these findings are in line with the notion that early use of antibiotics may predispose to obesity, it is important to not that these type of studies cannot prove causality. It may well be that other non-measured factors could explain this association (e.g. overprotective or lower SES parents may be more likely to use antibiotics in their infants – both factors are independently associated with higher rates of obesity). Nevertheless, given the rather high rates of antibiotic exposure in infants it appears that this may well be a promising area for further research not just in the context of obesity but also for many of the other conditions that are now believed to be influenced by intestinal flora. @DrSharma Edmonton, AB Azad MB, Bridgman SL, Becker AB, & Kozyrskyj AL (2014). Infant antibiotic exposure and the development of childhood overweight and central adiposity. International journal of obesity (2005) PMID: 25012772 .  

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Can Germs In Your Drinking Water Help Prevent Obesity?

In my show I joke about how I intend to import water from the river Ganges as a new obesity treatment that I will appropriately name “RunFast”. Jokes aside, a study by Zhongyi Chen and colleagues, published in the Journal of Clinical Investigation, shows that treating mice with genetically modified bugs delivered through their drinking water can protect them from becoming obese even when fed a high-fat diet. To be exact, the researchers used a strain of e coli bacteria genetically engineered to produce N-acylphosphatidylethanolamines (NAPEs), which are precursors to the N-acylethanolamide (NAE) family of lipids, normally synthesized in the small intestine in response to feeding and known to reduce food intake. As their study shows, administration of these modified bacteria in drinking water for 8 weeks dramatically lowered food intake, weight gain, body fat, insulin resistance and liver fat in mice on a high-fat diet. These “protective effects” lasted for at least 4 weeks after removal of these bacteria from the drinking water. In another set of experiments the researchers also showed that this strain of bacteria reduced weight gain in a genetic model of mouse obesity. Contrary to what one may believe, this study neither supports nor refutes the idea that gut bacteria may be partly responsible for the obesity epidemic. Rather, the study primarily shows that bacteria may be used as a delivery system for “therapeutic doses” of molecules to the intestines – in this case, resulting in the modification of appetite and metabolism. I would not be surprised if the therapeutic use of bacteria (genetically modified or not) opens up a whole new dimension of therapeutics – not just for obesity. @DrSharma Edmonton, AB Chen Z, Guo L, Zhang Y, L Walzem R, Pendergast JS, Printz RL, Morris LC, Matafonova E, Stien X, Kang L, Coulon D, McGuinness OP, Niswender KD, & Davies SS (2014). Incorporation of therapeutically modified bacteria into gut microbiota inhibits obesity. The Journal of clinical investigation PMID: 24960158

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