Fiber-rich diet may reduce preeclampsia risk during pregnancy, study finds
11 Jul 2019 --- Fiber-rich diets may prove important during pregnancy in boosting the wellbeing of both mother and child, as well as protecting against the serious pregnancy-related condition preeclampsia. This is according to Australian research, published in Nature Communications, which found that reduced levels of acetate, produced by fiber fermentation in the gut, is associated with preeclampsia. The researchers note that staple recommendations such as to “eat real food, mostly plants, and not too much” might be the most effective primary prevention strategy for some of the most serious conditions relating to pregnancy.
Preeclampsia occurs in up to 10 percent of pregnancies and is characterized by high blood pressure, protein in the urine and severe swelling in the mother. It also interferes with the child’s immune development whilst in the womb, with some evidence suggesting a link to higher rates of allergies and autoimmune disease later in life.
“The mother’s gut bacteria and diet appear to be crucial in promoting a healthy pregnancy,” says senior author of the study Professor Ralph Nana, from the University of Sydney School of Medicine and Charles Perkins Centre.
In the collaborative study from the University of Sydney’s Charles Perkins Centre, the Barwon Infant Study from Deakin University, Monash University, James Cook University and the Australian National University, the researchers set out to investigate the role of these metabolic products of gut bacteria during pregnancy.
The mother’s gut bacteria and diet appear to be crucial in promoting a healthy pregnancy.The findings showed that preeclampsia affected the development of an important fetal immune organ, the thymus, which sits just behind the breastbone. Fetuses in preeclamptic pregnancies were found to have a much smaller thymus than children from healthy pregnancies.
The cells that the thymus normally generates called T cells (thymus-derived cells) – specifically, those associated with the prevention of allergies and autoimmune conditions such as diabetes – also remained lower in infants after preeclampsia, even four years after delivery.
The mechanisms of acetate on the developing fetal immune system were further examined in separate experiments involving mice that showed acetate was central in driving fetal thymus and T cell development.
Together, these results showed that promoting specific metabolic products of gut bacteria during pregnancy might be an effective way to maintain a healthy pregnancy and to prevent allergies and autoimmune conditions later in life.
They may also partly explain the sharp increase of allergies and autoimmune conditions as Western diets are increasingly dominated by highly processed foods, which are very low in fiber, the researchers note.
“More studies are urgently needed to understand how we can best target this system to reduce the growing burden of immune-related diseases in the modern world,” says study co-author Peter Vuillermin, also co-lead of the Barwon Infant Study, a major birth cohort study being conducted by the Child Health Research Unit at Barwon Health in collaboration with the Murdoch Children's Research Institute (MCRI) and Deakin University.
Going forward, the researchers will conduct further clinical trials to test the effects of a high fiber diet during pregnancy on preeclampsia and allergies.
Previous research also showed that a high-fat diet may contribute to the impairment of the gut barrier during pregnancy, which can lead to metabolic shifts and impede fetal development. Previously, scientists had assumed that the changes in metabolism during pregnancy were entirely attributed to pregnancy hormones. Findings from the study, however, suggest that changes in the maternal gut microbiome may contribute to these metabolic changes. With this knowledge, researchers say there is a therapeutic opportunity to modify this microbial community during pregnancy to improve both maternal and offspring health.
Edited by Kristiana Lalou
