With the World Health Organization estimating that by 2015, there will be more than 1.5 billion overweight consumers, incurring health costs beyond $117 billion per year in the US alone, the opportunities for a scientifically-substantiated weight management food product are impressive.
A breakthrough paper published in Nature in December 2006 (Vol. 444, pp. 1022-1023, 1027-1031) reported that microbial populations in the gut are different between obese and lean people, and that when the obese people lost weight their microflora reverted back to that observed in a lean person, suggesting that obesity may have a microbial component.
“The role of the gut microbiota in affecting calorie control and satiety is gradually being unravelled"
- Professor Glenn Gibson, University of Reading
A recent study, published in Science Translational Medicine (Vol. 1, Issue 6, 6ra14), advanced this by successfully showing that the human gut microbiota can successfully be transferred to germ-free mice, and that this can then be passed on from mother to offspring.
The potential of prebiotics
Such links have led many to consider a role for prebiotics and probiotics to modify gut microflora.
Prebiotics are “non-digestible (by the host) food ingredients that have a beneficial effect through their selective metabolism in the intestinal tract” (Gibson et al. 2004), while probiotics are defined as “live microorganisms which when administered in adequate amounts confer a health benefit on the host” (FAO/WHO).
According to a new review of the science in this emerging area, Nathalie Delzenne and Patrice Cani from the Catholic University of Louvain report that data from animal studies supports the potential of prebiotics to beneficially manage metabolic diseases in overweight or obese patients. And the findings are being replicated in humans, they state in the International Dairy Journal.
The Belgium-based scientists note that data already exists showing that inulin-type prebiotics may reduce appetite, increase satiety, and thereby decrease the amount of energy consumed. However, such effects were only noted after several weeks and no such effects being observed over a 48-hour period.
These results suggested “that the adaptation of the gut microbiota is required to have a physiological relevance in the control of food intake. A decrease in body mass index, linked to a modulation of gut peptides and appetite, have been shown upon long term treatment of overweight and obese patients,” they noted.
The researchers also note that the concept may also apply to probiotics. “Moreover, the metabolomic analysis will allow to select the potential new microbial targets related to obesity and related disorders in the future,” concluded Delzenne and Cani.
Unravelling the role of microbiota
The review was welcomed as a “timely” by prebiotics expert Professor Glenn Gibson from the University of Reading.
Professor Gibson told NutraIngredients that, while there is no doubt that traditional risk factors like a poor diet, genetics, and a lack of exercise do contribute to obesity, “it may be argued that these alone cannot account for the explosive increase in obese related conditions during the last 10-15 years”.
“The role of the gut microbiota in affecting calorie control and satiety is gradually being unravelled.
“The authors admit that much of the data arises from model or animal experiments and they make a call for more human studies. However, the intriguing possibility exists that dietary induced alterations of the microbiota may be important for long term weight management and the control of metabolic disorder.
“If this story holds up, then the possibilities for tackling a predominant 21st Century health risk are huge,” added Professor Gibson.
Source: International Dairy Journal
April 2010, Volume 20, Issue 4, Pages 277-280
“Nutritional modulation of gut microbiota in the context of obesity and insulin resistance: Potential interest of prebiotics”
Authors: N.M. Delzenne, P.D. Cani