Matters of the heart: Increased fiber consumption may boost heart health

27 May 2019 --- Heart health patients who consume higher amounts of fiber tend to have a healthier gut microbiome, which is linked to a reduced risk of death or need of a heart transplant. This is according to a study presented yesterday at Heart Failure 2019, a scientific congress of the European Society of Cardiology (ESC). The researchers note that the findings should be further explored and that should they be confirmed, foods high in fiber such as cereals, fruits and vegetables should be chosen to stimulate a healthy gut flora.

“Our gut microbiota is composed of trillions of microorganisms that have the potential to affect our health,” notes study author Dr. Cristiane Mayerhofer, of Oslo University Hospital, Norway. “Previous research has reported reduced biodiversity of microbes in the gut of patients with heart failure patients. Today we show for the first time that this is related to low fiber intake.”

Heart health in relation to fiber
The new study also linked meat intake to higher levels of trimethylamine-N-oxide (TMAO) in patients with heart failure. Prior research has shown that increased TMAO levels are associated with a greater risk of cardiovascular events and that gut microbes play a role in its formation.

“We show an important pathway that connects diet, microbial activity, and cardiovascular disease,” says Dr. Mayerhofer. “It would be prudent for patients with heart failure to limit their meat intake to two to three times a week.”

To conduct the study, the investigators recruited 84 well-treated patients with chronic heart failure and 266 healthy people. The composition of gut microbes was assessed by sequencing the bacterial 16S rRNA gene in stool samples and compared between the two groups.

Heart failure patients had lower biodiversity of intestinal microbes than healthy controls, with differences in the two main phyla of bacteria present in the human gut. Patients with heart failure had a lower ratio of Firmicutes/Bacteroidetes (F/B) compared to controls and this difference was even more pronounced when the cause of heart failure was non-ischaemic. 

Dietary and outcome analyses were performed in heart failure patients. Patients who had a heart transplant or died had lower biodiversity and a lower F/B ratio than controls. Regarding diet, bacterial diversity and Firmicutes levels were positively associated with fiber intake.

“Our findings suggest that the altered microbiota composition found in patients with chronic heart failure might be connected to low fiber intake,” says Dr. Mayerhofer. 

“We are still just in the beginning of mapping and understanding the microbiota, how it works, and its potential for the clinical setting,” notes Dr. Mayerhofer.

She is currently involved with GutHeart, the first randomized controlled trial on the effect of a probiotic and an antibiotic on the composition of gut bacteria, heart function and inflammation in patients with heart failure. “The trial will show the potential clinical effects of modulating our gut bugs in the setting of heart failure,” she concludes. 

Rising demand for fiber is driving NPD
There is renewed interest in fiber, as consumers are still mainly consuming fiber for digestive health, but newly discovered health benefits are driving applications too. 

A large number of people do fall short on their recommended daily fiber intake, however. For example, earlier in 2018, a Public Health England (PHE) survey found that only nine percent of adults were achieving the daily intake goal of 30g. 

Product innovation within the fiber space suggests that this shortfall is being addressed in NPD. According to a 2018 consumer survey conducted by Innova Market Insights, 44 percent of US consumer are increasing their consumption of fiber, with 33 percent of UK consumers doing so. At the same time, 21 percent average annual growth has been reported in new product launches carrying a fiber claim. 

Newly discovered health benefits are driving rising consumer interest in fiber applications. When asked for reasons why they are consuming fiber, unsurprisingly the majority of US consumers (64 percent) listed digestive health, but interestingly weight management (24 percent) and energy (16 percent) also featured. The market researcher also notes an Innova Market Insights notes 55 percent average annual growth in new sports nutrition launches with a fiber claim (Global, CAGR 2013-2017).

More research on fiber and its benefits
Earlier this year, a Lancet study found that higher intake levels of dietary fiber and whole grains are being linked with a lower risk of non-communicable diseases, body weight and cholesterol levels. The research highlighted the importance of carbohydrate quality in our diets, which may be particularly salient as low carb diets continue to trend.

In relation to other noncommunicable diseases, a study published in the American Journal of Physiology-Endocrinology and Metabolism found that flaxseed fibers that ferment in the gut influence microbiota that can improve metabolic health, while protecting against diet-induced obesity. The study was carried out in mice and the data suggest that flaxseed supplementation may positively benefit obese individuals in reducing weight and improving glucose tolerance.

Moreover, dietary fiber may also shield against lung diseases, such as chronic obstructive pulmonary disease (COPD), as it boosts the production of anti-inflammatory short-chain fatty acids (SCFA). This is according to a mouse study from the Priority Research Centre for Healthy Lungs at the University of Newcastle, Australia and the Centre for Inflammation, which is a partnership between the University of Technology, Sydney and the Centenary Institute, Australia. The findings could prove useful for people at risk of COPD and help develop new therapeutic treatments.