Maternal Dietary Fibre May Improve Children's Long-Term Heart Health

Food choices during pregnancy may matter even more than previously thought.

A new study in pregnant mice indicates that a fibre-rich diet can improve the lifelong heart health of their developing offspring, substantially reducing the likelihood of cardiovascular disease in later life.

The result aligns well with existing nutritional guidance for expectant mothers, reinforcing the value of a balanced diet while a new person is developing.

"Dietary fiber, which is found in foods such as fruits, vegetables, and whole grains, is well-known for its health benefits," says biomedical scientist Francine Marques of Monash University in Australia.

"Our research shows that its impact extends beyond the mother, and can shape the development of her child's heart."

Maternal dietary fibre and offspring heart health

Deciding what to eat during pregnancy can feel like navigating a minefield. Avoid soft cheese. Eat more spinach. Steer clear of deli meats. Have yoghurt. In broad terms, though, the foundations are much the same as healthy-eating advice for anyone: eat plenty of dietary fibre, which supports bowel health and can lower cholesterol.

To investigate whether maternal fibre consumption affects fetal development, Marques and her team studied mice. They gave separate groups of pregnant and lactating mice either high-fibre or low-fibre diets. After weaning, the young mice were all given diets containing standard fibre levels.

How the mouse study tested cardiovascular disease risk

When one group of eight young mice reached six weeks old, the team carried out RNA sequencing on heart tissue. A high-fibre maternal diet was associated with hearts that responded less strongly to inflammatory and immune triggers, making them more resilient to relatively minor irritations.

The researchers then turned their attention to cardiovascular disease. They administered the hormone angiotensin to six-week-old mice to cause organ damage linked to hypertension. As hypertension, or high blood pressure, is a major cause of cardiovascular disease, this provided a useful measure of vulnerability.

Mice born to mothers on a low-fibre diet had hearts in considerably poorer condition than mice whose mothers ate more fibre. Their hearts were much larger, with thicker walls and greater collagen deposition. This indicated increased susceptibility to conditions including hypertrophic cardiomyopathy, where thickening of the left ventricle wall limits its ability to pump blood, and cardiac fibrosis, in which scar tissue forms in the heart.

Gut bacteria, short-chain fatty acids and fetal development

The scientists also found that mothers and offspring on high-fibre diets had healthier guts and gut bacteria. Mothers additionally had 50 percent higher blood plasma levels of short-chain fatty acids.

Fibre encourages the production of short-chain fatty acids in the gut. These compounds pass through the bloodstream to the placenta and then to the fetus, where they help influence gene activity in the developing heart.

The findings imply that the effects of a mother's diet before birth may have been underestimated, although more research will be required to establish whether the same results apply to humans. High-fibre diets are already known to help people maintain a healthy gut and microbiome, so it is reasonable to consider that pregnant people may receive these benefits too.

"Cardiovascular disease is a leading cause of death worldwide, and this research suggests that a simple dietary change during pregnancy could have lifelong benefits for children," Marques says.

"Our work adds to the growing body of evidence highlighting the importance of a healthy diet during pregnancy."

She advises mothers to keep working with their healthcare providers to ensure they really are eating for two, with both their own wellbeing and that of their baby in mind.

The findings were published in Circulation Research.