Without having to go to body builders’ extremes, it is widely accepted that building up muscle tissue through both aerobic and resistance exercise helps the body burn excess fat – even when it is at rest – by boosting its metabolic basal rate. If the encouraging results of recent research are anything to go by, […]
Without having to go to body builders’ extremes, it is widely accepted that building up muscle tissue through both aerobic and resistance exercise helps the body burn excess fat – even when it is at rest – by boosting its metabolic basal rate. If the encouraging results of recent research are anything to go by, keeping one’s intestinal microflora in good shape, as well as one’s muscles, will soon become an essential string in the dieter’s bow en route to long-term sustained weight management.
Level of fat uptake heavily influenced by gut bacteria
The human intestinal tract contains up to 2kg of bacteria, and their impact on health – both positive and negative – is a matter of ongoing investigation. There is a definite link, for example, between the gut microflora composition and body weight.
A handful of studies in this field are widely regarded as seminal – for example, a Washington University (St Louis) study published in 2006 in the prestigious journal Nature, which not only showed that obese people’s intestinal microflora differed from that of lean people, but that, as the excess weight was shed, the overweight subjects’ intestinal flora composition changed to resemble that of a lean person.
In August 2014, an intriguing study surfaced in the journal Cell, entitled “Altering the Intestinal Microbiota during a Critical Developmental Window Has Lasting Metabolic Consequences”. Researchers from the New York University (NYU) Langone Medical Center found that exposure to antibiotics during infancy caused disruption in the intestinal microflora, resulting in a higher risk of obesity in adulthood, particularly in males. The researchers said that early exposure to antibiotics killed off certain types of beneficial bacteria, causing people to gain more weight if they were consuming a high fat diet.
And this is not the only study linking gut bacteria, a high fat intake and weight gain. A very recent study carried out by the German Institute of Human Nutrition Potsdam-Rehbrücke, published in October 2014 in mBio, discovered that one specific species of gut bacteria, Clostridium ramosum, boosted fat uptake from the small intestine. In rodents that had been equipped with human gut bacteria, animals harbouring Clostridium ramosum gained significantly more weight on a high fat diet than those free of that bacterium, even if dietary energy intake was equal.
As health and wellness trend watchers will be aware, the low-fat diet approach to weight loss has somewhat fallen out of favour in recent years, but research findings such as these highlight the fact that cutting down on dietary fat may be a highly effective strategy for some overweight individuals. Gut microbiota composition differs from person to person, and one glove certainly does not fit all.
Manipulating the microflora
However, the aforementioned NYU researchers felt confident that an optimum bacterial balance could indeed be restored, and they are not the only ones to suggest this. The concept that the intestinal microflora can be modified in a targeted way to optimise digestive and metabolic functioning is the fundamental premise of the probiotics industry, which, by now, is supported by a formidable body of science.
For instance, in April 2013, a Japanese research team reported in the British Journal of Nutrition that a daily dose of 100 million colony forming units of Lactobacillus gasseri SBT2055 for twelve weeks resulted in a 4.6% reduction of abdominal fat and 3.3% reduction in subcutaneous fat in study subjects enlisted in a randomised controlled trial. The bacteria were administered in a fermented milk product provided by Megmilk Snow Brand Company, Japan’s second-ranking dairy company. The researchers pointed out, though, that the fat loss benefits were not maintained once probiotic intake was discontinued.
Canadian researchers have also discovered in a randomised controlled trial that daily probiotic yoghurt consumption could reduce body fat levels by up to 4%. The team employed Lactobacillus amylovorus and Lactobacillus fermentum (provided by Micropharma Limited) for a duration of six weeks, and concluded that the intake of these bacteria created a microflora, which favoured fat burning over fat storage. The study was published in the Journal of Functional Foods in November 2012.
Don’t forget prebiotics
It has long been evident that the gut microflora is a very transient ensemble rather than a fixed entity. It may be influenced, perhaps even to quite a significant extent, through the consumption of probiotic bacteria, but the daily diet, in itself, has a far reaching impact on gut flora composition. Even mundane, everyday foods can effect noteworthy changes in its make-up.
In September 2014, Washington State University published a study in Food Chemistry, reporting that obese mice that were fed apples, experienced a change in their intestinal flora composition to the extent that it ended up resembling that of lean mice.
Based on these results and other similar studies, researchers believed that the intake of non-digestible compounds contained in apples, like dietary fibre and polyphenols, helped to stabilise a number of metabolic processes also in humans, including those implicated in producing a feeling of satiety.
It is worth mentioning that beneficial compounds contained in the apples managed to reach the colon unharmed, despite exposure to chewing, stomach acid and other digestive juices. By contrast, the low rate of survival of unprotected probiotic bacteria during their journey through the human digestive tract has long been a major bugbear for probiotic ingredients suppliers, although recent advancements in probiotic dietary supplement formats, like the patented BIO-tract delivery system from Nutraceutix, or Probiocap from Institut Rosell-Lallemand help overcome these challenges.
Fibres that are indigestible for humans, but not for beneficial microorganisms populating the human gut for which these fibres serve as a food source, are commonly referred to as prebiotics.
The evidence that the composition of the intestinal microflora has a significant impact on metabolic processes, including on the conversion of dietary fat to body fat, is pretty much irrefutable at this stage. More research needs to be done on uncovering the mechanisms and also on the most effective ways of modifying the microbiota to achieve optimum results in terms of weight management.
However, it is already foreseeable that, in the not-too-distant future, this approach will constitute a standard component of the weight management toolkit, and considering that the consumption of food and beverage products with added pre- and probiotics is generally much less of an effort for the average consumer than a low fat diet or physical exercise, it is bound to find a positive reception.