Can fibre reduce your chances of contracting colon cancer?
I have been a fan of Dr Michael Greger for some considerable time. He excels at explaining important and often complex nutrition research in a way that most people can understand. Michael recently wrote about the benefits of fibre to health, its crucial role in feeding the ‘good’ gut bacteria. Put simply out gut bacteria converts fibre into short-chain fatty acids (SCFA). SCFAs deliver a range of benefits and are thought to reduce the chances of contracting colon cancer.
It’s not simply that SCFA promote gut health generally, fibre helps to maintain gut flora. A failure to eat enough fibre can lead to the starvation and decline of healthy bacteria. This typically allows for an imbalance (dysbiosis), where potentially harmful bacteria begin to dominate, perhaps leading to a range of inflammatory diseases and even colon cancer. Further links even suggest a connection to cardiovascular disease, metabolic syndrome and type 2 diabetes.
A relative small amounts of fibre is needed to sustain healthy gut bacteria, in many cases just a handful of chickpeas every day. And yet there is evidence that many people in the USA and UK are failing to include sufficient fibre into their daily diet.
Kefir appears to offer significantly greater benefit than commercially produced probiotic drinks.
Dr Michael Mosley has been helping to run a study for the BBC looking at the relative benefits to gut health from a range of products. Volunteers and scientists collaborated to try to discover which of three probiotics/prebiotics had the biggest positive impact on gut bacteria.
The first product was a commercially available drink, branded as a probiotic and available in major supermarkets. The second item up for comparison was kefir, a traditional milk and yeast fermented substance, a little like yogurt. These first two foods were compared with vegetables high in natural prebiotic fibre called inulin. Inulin is found in range of foods including chicory (chicory root is a rich source) and scallions (onions, leeks and garlic).
The poorest preforming of the three in this trial was the probiotic drink. The participants in this group demonstrated a modest (statistically non significant) change in lachnospiraceae gut bacteria. Conversely significant changes in gut flora were seen in the group consuming prebiotic fibre. The people that consumer kefir enjoyed the most positive increase to gut bacteria.
It should be pointed out that any comparison between prebiotics and probiotics is not a like for like test. Prebiotics deliver the food that supports existing bacteria and create the conditions for further colonization. A probiotic is intended to introduce microorganisms directly into the body.
The BBC study concluded that traditionally produced fermented foods (or even home made versions) may offer the greatest benefits to consumers in terms of increased gut flora. A key problem with mass produced fermented foods and drinks is pasteurisation. Pasturised goods are regarded as safer, which also correlates to a longer shelf life. By comparison traditionally made kefir has to be consumed in a relatively short space of time. This is perhaps the choice we consumers face, if we want maximum health benefits from the food we make or buy we may have to sacrifice some of the convenience of long sell by dates.