A team of researchers have now discovered how the 'good' bacteria in our gut communicates with our own cells, thereby establishing the basis of a successful relationship.This is a key step in understanding how our bodies maintain a close relationship with the population of gut bacteria that plays crucial roles in maintaining our health, fighting infection and digesting our food.
A study, published in the journal Cell Reports
, shows that the gut bacteria produce an enzyme that modifies signalling in cells lining the gut. The enzyme also has another role in breaking down food components."Our study provides a breakthrough in understanding how bacteria communicate across different kingdoms to influence our own cells' behaviour, as well as how we digest our food," said Dr Regis Stentz from the IFR, which is strategically funded by the Biotechnology and Biological Sciences Research Council.
We all rely on trillions of bacteria in our gut to break down certain components of our diet. One example is phytate, the form phosphorus takes in cereals and vegetables. Broken down phytate is a source of vital nutrients, but in its undigested form it has detrimental properties. It binds to important minerals preventing them being taken up by the body, causing conditions like anaemia, especially in developing countries. Phytate also leads to excess phosphorus leaching into the soil from farm animal waste, and feed supplements are used to minimise this.
But despite the importance of phytate, we know very little about how it is broken down in our gut.To address this Dr Stentz and colleagues screened the genomes of hundreds of different species of gut bacteria. They found, in one of the most prominent gut bacteria species, an enzyme able to break down phytate. In collaboration with Norwich Research Park colleagues at the University of East Anglia, they crystallised this enzyme and solved its 3D structure.
They then went on to characterise the enzyme, showing it was highly effective at processing phytate into the nutrients the body needs. The bacteria package the enzyme in small 'cages', called outer membrane vesicles (OMVs) which allow phytate in for nutrient processing but prevent it being destroyed by our own protein-degrading enzymes. This releases nutrients, specifically phosphates and inositol, which can be absorbed by our own bodies, as well as the bacteria.