Unique riboflavin-producing properties of AMBV339  

The ultimate moment has arrived! Get to know Limosilactobacillus reuteri AMBV339, also known as the unique vaginal inhabitant that quickly conquered our Isala hearts as a riboflavin producer. 😊

Riboflavin? Riboflavin is better known as vitamin B2. As part of the important group of B vitamins, this vitamin helps us in our daily energy metabolism. Dairy products (e.g., milk) but also other foods, such as grains and green vegetables, are important sources of riboflavin in our diet. By the way, did you know that riboflavin is broken down when exposed to light? This is one of the reasons why you won’t see milk in glass bottles that often anymore. A riboflavin deficiency manifests itself in cracking at the corners of the mouth, a swollen tongue and skin disorders. Furthermore, shortage of this vitamin can even be linked to growth problems.

Why is vitamin B production of such large interest for the Isala research team? First of all, riboflavin is essential during pregnancy. This vitamin is important for the growth of the baby and the development of his/her immune system. Riboflavin is taken up within the placenta and thus reaches the foetus. That is why it is recommended that pregnant women have a higher riboflavin intake than usual! Furthermore, breast milk contains riboflavin as well. In this way, this vitamin contributes to the name ‘liquid gold’. Of course, the losses of riboflavin via breast milk must be compensated, which brings us to the higher riboflavin requirement during breast feeding. Therefore, the discovery of a riboflavin-producing bacterium is considered of great importance for the Isala research.

Applications in food? Wait a second? If riboflavin is an important part of the diet of (pregnant) women, and if lactobacilli are not only present in your vagina but also in food, isn’t it possible to make food products that contain AMBV339 and as such administer riboflavin in a natural way? We admit: for people outside our lab, this sounds as a crazy idea at first sight. 😉 But when you look at it from a distance, it’s not that strange to investigate the addition of AMBV339 (of course very clean and purified 😉) to whole and semi-skimmed cow milk and buttermilk, as well as to plant-based alternatives based on coconut, soy and oat. These milk alternatives are becoming increasingly popular but are often low in riboflavin. That is why enrichment of such plant-based foods is important to avoid riboflavin deficiencies. It turned out that our original idea wasn’t that bad: we observed that AMBV339 did an excellent job in the coconut beverage, with high levels of riboflavin production. Furthermore, the bacterium produced a considerable amount of this vitamin in butter milk as well. We were immediately excited and were looking forward to further investigate the beneficial effect of this bacterium on female health! 😊

Mimicking the effects in our digestive system? With great enthusiasm, we went to the NatuRA lab of the University of Antwerp to make use of their self-designed GIDM-colon model. In short, this ‘Gastro-Intestinal Dialysis Model’ mimics the digestive system as it can be found in your and my body on a lab scale. In this way, we could learn more about the passage of the coconut beverage containing AMBV339 and riboflavin through different parts, namely the stomach, small and large intestine. Here too, we got positive results. For example, we observed that AMBV339 survives the acidic gastric juice and we noticed riboflavin production in the model as well as uptake of riboflavin into intestinal cells. We even investigated the combination of AMBV339 with a bacterium commonly used in yogurt production processes (namely Streptococcus thermophilus) and again got promising results. This is definitely interesting as we start thinking about administering AMBV339 to women in real life. How cool would that be!? 😊

We can go on for a while by summarising great experiments. All together, we learned more and more about AMBV339 every time, which tasted sweet as a delicious cake. 😊 Now you might also expect a cherry on that cake… And yes, there definitely was one, being the publication of a very interesting scientific article in the journal ‘Frontiers in Nutrition’ about the promising potential of AMBV339. For sure, this vaginal bacterium already conquered our Isala hearts. Yours too? 😊

Who am I?
My name is Isabel Erreygers. Together with you, I would like to reflect on my final thesis year. While studying to become a bio-engineer, I could opt for a master’s thesis on a hot topic (yes, I mean the vaginal microbiome) while being surrounded by an excellent team of Isala researchers. Of course I didn’t have to think twice about that. Now I look back on it with great satisfaction and I am proud of the final result as well. Or should I better describe it as the beginning of even more exciting science? 😊

The past academic year was probably the busiest period in my ‘school career’, but one that was very fascinating and extremely interesting. I enjoyed commuting by train between Leuven and Antwerp for following the courses on one hand and conducting lab research on the other with the best supervisory team I could wish for. Every time again, I was welcomed with open arms in the lab where the Isala team conducts excellent research. We carried out many different experiments with AMBV339 and worked hard to make progress in the very interesting, exciting and fascinating field of vaginal microbiome research.

As a co-author, I was allowed to contribute to the scientific research article about AMBV339, which really felt like a nice reward for all the hard-working and busy days of the past few months. Last but not least, I would like to share one more recent update on the future that colours pretty rosy. After an interesting bachelor project and a fascinating master’s thesis in the lab of Prof. Sarah Lebeer, I may tell you that the Isala story will be continued for me personally, this time as a PhD student. I am really looking forward to it! 😊