Obesity and the microbiome

Abstract

Obesity constitutes a significant and rapidly increasing public health challenge and is associated with significant co-morbidities and healthcare costs. Although undoubtedly multifactorial, research over the last decade has demonstrated that the microbes that colonize the human gut may contribute to the development of obesity through roles in polysaccharide breakdown, nutrient absorption, inflammatory responses and gut permeability. Studies have consistently shown that the Firmicutes to Bacteroidetes ratio, in particular, is increased in obesity and reduces with weight loss. In addition, we and others have shown that the methanogenic Archaea may also contribute to altered metabolism and weight gain in the host. However, much remains to be learned about the roles of different gut microbial populations in weight gain and obesity and the underlying mechanisms before we can begin to approach targeted treatments.

Global Change and the Soil Microbiome: A Human-Health Perspective

“…Recognizing and understanding the similarities and deep connections between the gut and the belowground world, where roots are the equivalent to our gut and the rhizosphere is the gut microflora (Berendsen et al, 2012) can help us advance the understanding of ecosystems by leaps and bounds through the search of similar microbial indicators of disease (e.g., Bacteroidetes to Firmicutes ratio in humans; Mathur and Barlow, 2015) and, therefore, to implement quick and successful measures in ecosystem management rather than relying, perhaps naively, on that the very same thing that caused climate change (i.e., pollutant emissions to the atmosphere) will also be part of the solution. From here, I advocate for the development of a new field of research that specifically aims at recognizing and make practical use of the profound links between the functioning of the gut and the ecosystems that extend beyond our bodies and that benefits from a truly multidisciplinary collaboration among experts in the areas of global change ecology and human health.…”

“…In this sense, it has been repeatedly shown through experimental studies and meta-analyses that increased N deposition is typically associated with changes in soil microbial communities (usually related to a decrease in abundance and biodiversity ;Treseder, 2004Treseder, , 2008Ramirez et al, 2010;Zeng et al, 2015), reduced ecosystem functionality (alterations of energy metabolism; Waldrop and Zak, 2006;Treseder, 2008;Liu et al, 2014) and short-to mid-term increases in C sequestration, especially in aboveground biomass, but also in the soil and roots (comparable to obesity, as previously mentioned; Xia and Wan, 2008;Yue et al, 2016). Given that metabolic disorders and obesity in humans are clearly associated with a deterioration in the health status of individuals that may even result in cases of fatality due to chronic diseases, sudden death or, quite commonly in the natural world, to increased sensitivity to other environmental stresses (Mathur and Barlow, 2015;Monteiro et al, 2015), I think that we would do well to be cautious when we consider, perhaps naively, the potential benefits of a N that, after all, is the result of the atmospheric pollution derived from our activities (Gruber and Galloway, 2008).…”

“…The connections between human health, disease, and the microbiome, especially in the case of the gut, are becoming increasingly apparent and are attracting the public attention, especially because of the high social cost of unhealthy dietary habits and lifestyles and the "deceptively simple" solution of the problem (Mathur and Barlow, 2015;Tilg and Adolph, 2015;Blaser, 2016). In the case of both people and ecosystems, (i) ensuring a healthy supply of nutrients derived from the breakdown and cycling of unprocessed food/organic matter, (ii) minimizing the use of antibiotics (particularly those associated Higher fungal to bacterial biomass and activity ratio.…”

“…Of course, there are opportunities to aid in the recovery of our damaged and degraded ecosystems as well as there are possibilities to recover the lost or damaged intestinal flora (Brudnak, 2002;Sheth et al, 2016). This can be achieved by the use of properly designed probiotics or fecal transplants or, in the case of ecosystems, inocula assembled in the lab from pure cultures or soil samples obtained in the field from healthy ecosystems (Bowker, 2007;Chiquoine et al, 2016;Wubs et al, 2016) in conjunction with a balanced nutrient supply (i.e., organic matter inputs, the equivalent to prebiotics; Mathur and Barlow, 2015;Sheth et al, 2016). In this sense, the concept of synbiotics (i.e., synchronous administration of probiotics and prebiotics) could represent a particularly promising benchmark borrowed from the human health literature to successfully restore degraded ecosystems (Tang and Lodge, 2016) and, thus, the human probiotics industry has an opportunity to play a key role in this development.…”

Abnormality in Maternal Dietary Calcium Intake During Pregnancy and Lactation Promotes Body Weight Gain by Affecting the Gut Microbiota in Mouse Offspring

“…However, the mechanism of obesity is still not clear and obesity prevention is challenging . During the past decade, the effects of gut microbiota on energy intake, homoeostasis and storage, and the development of obesity have received more attention . The microbiota chiefly ferments intestinal nondigestible carbohydrates which produce short chain fatty acids (SCFAs) and thereby supply energy to the host.…”