Food science potential: How fibre-rich formulations could minimise gut and kidney harm caused by processed foods

A recent study by Australia's Monash University has shown that a diet high in processed foods brings on leaky gut syndrome, which in turn increases the risk of kidney disease.

In particular, the findings revealed that certain harmful chemical compounds called Advanced Glycation End Products (AGEs), triggered by a process called the Maillard reaction, switch on the body's danger signals leading to an inflammatory response and chronic kidney disease.

However, by introducing foods containing a specialised fibre – a prebiotic in the form of high-amylose maize starch type 2 (HAMS-R2) - the effects can be improved.

These AGEs, found in heat treated or processed food is what gives browned, roasted, fried, grilled and baked foods its flavour and aroma.  

They are common in potato chips, bread, bakery products, chocolate and confectionery, because they add flavour and lead to the palatability and sensory properties of food.

Processed food consumption has long been associated with the risk of all-cause mortality, diabetes, hypertension, obesity, cancer and gastrointestinal diseases. However, understanding of the specific mechanisms by which processed foods impact human health is in its infancy.

This rodent-based study, published in Science Advances and led by Associate Professor Melinda Coughlan from Monash Central Clinical School, showed the inflammatory response could be switched off by introducing foods containing the high resistant starch fibre.

The gut bacteria ferments the fibre producing metabolites that are anti-inflammatory, restoring gut health and improving kidney health.

“Now that we have shown that it is certain chemical compounds found in highly processed foods that play a role in chronic kidney disease, we canlook to make alternative food formulations or functional foods aimed at dampening the body’s response,”​ said Associate Professor Coughlan.

“Given the increasing interest in the effects of processed food on health, we believe that these findings represent an important step towards understanding and countering the detrimental features of the modern diet. Dietary change, as with most behavior change, can be difficult to maintain long term, but by adding more foods high in resistant starch fibre and steaming and stewing cooking practices we can help dampen the harmful effects.”​

Writing in the journal Science Advances, they concluded: “​Together, we provide evidence that chronic consumption of processed foods induces impaired intestinal barrier permeability and complement pathway activation and confers microvascular disease risk in rodents. ​

“Pharmacological inhibition of the proinflammatory C5a-C5aR1 axis prevents the deleterious effects of processed food intake. Last, we illustrate that a gut targeted dietary intervention limits the negative influence of the modern, processed diet, providing a practical way for food products to be better formulated to limit health consequences.”​

A clinical trial, in collaboration with Associate Professor Jane Muir, from the Department of Gastroenterology, Monash Central Clinical School, and the Associate Professor Elif Ekinci, head of Diabetes at Austin Hospital/Melbourne Medical School, University of Melbourne, is now in planning for this year, to give people with early diabetic kidney disease a resistant starch supplemented food to study its effects on kidney health.

Source: Science Advances​

DOI: 10.1126/sciadv.abe4841

“Processed foods drive intestinal barrier permeability and microvascular diseases”

Authors: Melinda T. Coughlan, et al​