For some people, mention the word "gut" and you’ll immediately get a response on how they’re trying to trim their waistline or maybe how they have a "gut ache." In any case, the gut is not often referred to in a positive light.
However, the gut plays a vital role in the digestive process, allowing foods to be broken down and giving the body the ability to absorb required nutrients. Everything from soup to soda pop passes through the gastrointestinal (G.I.) tract on its way to the gut, where a massive colonization of good and bad bacteria congregate.
A lack of protective enzymes or beneficial bacteria may result in irritable bowel syndrome, constipation, diarrhea, gas, bloating and leaky gut, which releases viruses, bacteria, yeast and other toxins into the body. Worse yet, the body’s response to these toxins may cause plaque buildup and tumors.
Understanding the impact of the good and bad bacteria remains a challenge, but recent research is under way to help shed light on how improving gut health may lead to overall better health and wellness.
Concerns about carbs
Although the peak of the low-carbohydrate craze is long gone, research into the impact such diets and lifestyle changes have on health and wellness continues. One area that has received increased attention in recent weeks is the role a diet low in carbohydrates may have on gut health.
Scientists at the Rowett Research Institute in Scotland recently found a low carbohydrate weight loss diet resulted in a four-fold reduction in the amount of bacteria in the gut of obese men. The bacteria produce butyrate, a substance shown to be instrumental in keeping the gut healthy, including helping to prevent colorectal cancer. The sharp reduction in bacteria, and subsequently butyrate, raised researchers’ concerns that prolonged use of very low carbohydrate diets may have a negative effect on gut health.
As part of the study, researchers gave 19 healthy, obese men three diets containing either a high, medium or low level of carbohydrates. Two of the diets also contained a high proportion of protein, which is known to help reduce appetite and is used in a number of diets to help produce weight loss. In both of the high protein diets, volunteers lost similar amounts of weight and body fat.
"The changes in butyrate production that we observed in this study are the largest ever reported in a human dietary trial," said Harry Flint, who led the research at the Rowett Research Institute. "The results provide strong evidence that butyrate production is largely determined by the content of a particular type of carbohydrate in the diet that the bacteria in our guts can utilize.
"We can’t be sure from this study about the impact of butyrate production on gut health, but there has been quite a lot of work done that shows that butyrate stops cancer cells from growing, and so helps prevent colorectal cancer.
"If low-carbohydrate diets are to be consumed for long periods of time, it may be important to ensure that there is enough of the right sort of carbohydrate in the diet that can be used by the bacteria to produce compounds such as butyrate, which are beneficial for human health. This means making sure you continue to eat plenty of sources of fiber — such as fruit and vegetables."
Buckwheat helps control cholesterol
A study in The Journal of Agriculture and Food Chemistry suggests eating buckwheat protein may reduce cholesterol absorption in the gut.
While animal studies already have shown a link between consumption of buckwheat protein and decreases in serum cholesterol levels, the latest research from scientists at Standard Process Inc. and the University of Wisconsin-Madison showed a similar link using a human intestinal cell model. Standard Process Inc. is a Palmyra, Wis.-based maker of nutritional whole food supplements.
The study, "Insoluble Fraction of Buckwheat (Fagopyrum esculentum Moench) protein Processing Cholesterol-Binding Properties that Reduce Micelle Cholesterol Solubility and Uptake by Caco-2 Cells," looked at how buckwheat protein modulated cholesterol uptake in Caco-2 cells from micelles to better understand a possible mechanism of action in the gut. A micelle is an aggregate of surfactant molecules dispersed in a liquid colloid.
"When we conducted the cholesterol binding experiments in vitro, we found that a large proportion of the cholesterol was associated with an insoluble fraction of buckwheat protein," said Brandon Metzger, research scientist at Standard Process and a Ph.D. candidate in nutritional sciences at U.W.-Madison.
Mr. Metzger said cholesterol uptake in Caco-2 cells was cut by as much as 47% in the presence of buckwheat protein, suggesting a strong binding capacity that reduces the amount of cholesterol that integrates into micelles.
"Considering that the gut contains such a large pool of cholesterol, dietary interventions like buckwheat protein may be effective in altering cholesterol levels," Mr. Metzger said.
Mr. Metzger is part of a five-person team in the biological research laboratory at Standard Process. The researchers are expected to further evaluate how manufacturing processes might affect the content of buckwheat protein in the seed flour and how buckwheat protein might be enriched with current protein production methods.
In addition to reducing cholesterol, buckwheat proteins are gluten free and are recommended for celiac patients as an alternative to wheat products.
A cup of coffee for your health
Another study appearing in The Journal of Agriculture and Food Chemistry raises the possibility that consuming coffee may be good for the gut. The study, led by a research team in Germany, found coffee’s dietary fiber to be a good food for gut microflora.
According to the study, humans’ gut microbes ferment fiber from coffee, creating beneficial compounds. After isolating a mix of the gut-friendly bacteria belonging to the Bacteroides and Prevotella groups, researchers fermented the bacteria for a 24-hour period. Subsequently, they found that bacteria in the groups showed a 60% growth boost after encountering the coffee fibers.
Bacteroides are an intestinal bug that does not require oxygen. Most importantly, they assist in breaking down food products and supply some vitamins and other nutrients that humans cannot make. Bacteroides also serve as a guard against harmful bacteria, creating acids that help lower the gut’s pH to an acidity level many other germs cannot handle.
Proteins and peptides
Leatherhead Food International (L.F.I.), an English company, is accepting collaborators for a new research initiative to determine if proteins and peptides contribute to gut health.
The project, "Proteins & Peptides — Do They Contribute to Gut Health," was launched in response to interest from the food and beverage industry in development of functional or designer food products that may stimulate growth of friendly bacteria in the gut.
"Peptides are receiving immense attention for their bioactive properties such as lowering the blood pressure and prevention of dental caries," the L.F.I. said. "There has been some indication that certain peptides with specific amino acid sequences could function as prebiotics, defined as ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of healthy bacteria in the colon."
Because peptides are absorbed in the stomach, the L.F.I. said it’s worthwhile to conduct further research on using peptide-oligosaccharide blends, specifically looking at the blends’ stability in the G.I. following different blending procedures, examining the affect on the composition of the gut microflora, and looking at performance in selected food systems.
The deadline for participating in the project is Sept. 28.
This article can also be found in the digital edition of Food Business News, August 7, 2007, starting on Page 35. Click