Nav: Home

High dietary fiber intake linked to health promoting short chain fatty acids

September 28, 2015

Eating a lot of fibre-rich foods, such as fruit, vegetables, and legumes--typical of a Mediterranean diet--is linked to a rise in health promoting short chain fatty acids, finds research published online in the journal Gut.

And you don't have to be a vegetarian or a vegan to reap the benefits, the findings suggest.

Short chain fatty acids (SCFAs), which include acetate, propionate, and butyrate, are produced by bacteria in the gut during fermentation of insoluble fibre from dietary plant matter. SCFAs have been linked to health promoting effects, including a reduced risk of inflammatory diseases, diabetes, and cardiovascular disease.

The researchers gathered a week's information on the typical daily diet of 153 adults who either ate everything (omnivores, 51), or were vegetarians (51), or vegans (51), and living in four geographically distant cities in Italy.

They also assessed the levels of gut bacteria and the 'chemical fingerprints' of cellular processes (metabolites) in their stool and urine samples.

The Mediterranean diet is characterised by high intake of fruit, vegetables, legumes, nuts and cereals; moderately high intake of fish; regular but moderate alcohol consumption; and low intake of saturated fat, red meat, and dairy products.

Most (88%) of the vegans, almost two thirds of the vegetarians (65%), and around a third (30%) of the omnivores consistently ate a predominantly Mediterranean diet.

The investigation showed distinct patterns of microbial colonisation according to usual dietary intake.

Bacteroidetes were more abundant in the stool samples of those who ate a predominantly plant based diet, while Firmicutes were more abundant in those who ate a predominantly animal products diet. Both these categories of organisms (phyla) contain microbial species that can break down complex carbohydrates, resulting in the production of SCFAs.

Specifically, Prevotella and Lachnospira were more common among the vegetarians and vegans while Streptococcus was more common among the omnivores.

And higher levels of SCFA were found in vegans, vegetarians, and those who consistently followed a Mediterranean diet.

Levels of SCFAs were also strongly associated with the quantity of fruit, vegetables, legumes, and fibre habitually consumed, irrespective of the type of diet normally eaten.

On the other hand, levels of trimethylamine oxide (TMAO)--a compound that has been linked to cardiovascular disease--were significantly lower in the urine samples of vegetarians and vegans than they were in those of the omnivores.

But the more omnivores closely followed a Mediterranean diet, the lower were their TMAO levels, the analysis showed.

TMAO levels were linked to the prevalence of microbes associated with the intake of animal proteins and fat, including L-Ruminococcus (from the Lachnospiraceae family).

Eggs, beef, pork and fish are the primary sources of carnitine and choline--compounds that are converted by gut microbes into trimethylamine, which is then processed by the liver and released into the circulation as TMAO.

The researchers point out that SCFA levels can naturally vary as a result of age and gender, and their study did not set out to establish any causal links.

But they nevertheless suggest that the Mediterranean diet does seem to be associated with the production of health promoting SCFAs.

They conclude: "We provide here tangible evidence of the impact of a healthy diet and a Mediterranean dietary pattern on gut microbiota and on the beneficial regulation of microbial metabolism towards health maintenance in the host."

And they add: "Western omnivore diets are not necessarily detrimental when a certain consumption level of [plant] foods is included."
-end-


BMJ

Related Vegetables Articles:

Using enticing food labeling to make vegetables more appealing
Does labeling carrots as 'twisted citrus-glazed carrots' or green beans as 'sweet sizzilin' green beans and crispy shallots' make them more enticing and increase vegetable consumption?
Herbs, spices on vegetables may increase their appeal to men, young adults
Seasonings may entice adults -- especially men and people under age 50 -- who don't generally eat vegetables at lunchtime into increasing their vegetable intake, suggests a new study led by Joanna Manero, a graduate student in food science and human nutrition at the University of Illinois.
Eating more fruits and vegetables may lower risk of blockages in leg arteries
Eating three or more servings of fruit and vegetables per day may lower your risk of developing blockages in leg arteries.
Frozen fruits and vegetables help Americans achieve nutrition goals
New research presented today via poster presentation at the 2017 Experimental Biology meeting shows consumers who eat frozen fruits and vegetables eat more fruits and vegetables overall.
Fruits and vegetables' latest superpower? Lowering blood pressure
New study by Keck School of Medicine of USC researcher links increased dietary potassium with lower blood pressure.
More Vegetables News and Vegetables Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#534 Bacteria are Coming for Your OJ
What makes breakfast, breakfast? Well, according to every movie and TV show we've ever seen, a big glass of orange juice is basically required. But our morning grapefruit might be in danger. Why? Citrus greening, a bacteria carried by a bug, has infected 90% of the citrus groves in Florida. It's coming for your OJ. We'll talk with University of Maryland plant virologist Anne Simon about ways to stop the citrus killer, and with science writer and journalist Maryn McKenna about why throwing antibiotics at the problem is probably not the solution. Related links: A Review of the Citrus Greening...