HYA-fatty acid combats bacterial gastric diseases in mouse model experiments
The human digestive system is host to many kinds of bacteria: some friendly, probiotics types, and other kinds that are harmful. Identifying metabolic processes that can differentiate between these two types of bacteria is important to develop treatments for diseases caused by unfriendly bacteria.
Menaquinone (MK) a molecular compound produced by bacteria in the gut that can be synthesized by two different pathways. Of the two, the ‘futalosine pathway’ is not present in most probiotics. Researchers have studied this difference between the two kinds of bacteria and discovered molecules that only block the futalosine pathway, thereby inhibiting MK synthesis in harmful bacteria. Dietary fatty acids are an example of molecules exhibiting such blocking properties.
Polyunsaturated fatty acids are an integral component of the human diet and have many different structures. Of these, omega-3 and omega-6 fatty acids have especially stood out because of their health benefits for the heart and brain. Furthermore, in model experiments using mice, a team of researchers at Kitasato University, Japan, showed the ability of these fatty acids to diminish colonies of the bacteria Helicobacter pylori that causes gastric diseases. Their findings showed that some omega-3 and omega-6 fatty acids could block the futalosine pathway in H. pylori and greatly reduce the presence of H. pylori in the digestive tract of mice.
Recently, this team reported on a novel fatty acid: 10- hydroxy- cis- 12- octadecenoic acid (HYA), that is synthesized by gastrointestinal microbiota in the body. HYA is formed from linoleic acid (an omega-6 acid) by bacterial conversion. The researchers first measured the effects of HYA on H. pylori colonies grown in culture plates, and found that HYA suppressed many different strains of the bacteria. These effects were however not seen when MK was artificially added to the medium, implying that blocking MK synthesis was its mechanism of action.
These effects were then extended to two different mouse models of infection. When mice infected with H. pylori were fed with water containing HYA for three weeks, they were much less prone to gastric infections. Notably, HYA was also the most effective in preventing infection compared to other fatty acids. The bacteria Helicobacter suis cause a form of gastric cancer, and mice infected with H. suis showed significantly less cancerous tissue and tumour markers over a six month trial after HYA treatment.
The authors are optimistic that, “daily supplementation with HYA, a hydroxy monounsaturated fatty acid, would prevent Helicobacter- associated gastric diseases through its antibacterial activity.” It’s remarkable how something synthesized by one member of the bacterial species can be used to fight other members of the same species.
Hidenori Matsui1, Tetsufumi Takahashi(2), Somay Y. Murayama(3), Marina Kawaguchi(4), Koichi Matsuo(5), Masahiko Nakamura(6) .“Protective efficacy of a hydroxy fatty acid against gastric Helicobacter infections.” Helicobacter, 22, e12430, (2017).
Published online August 2017
Authors and affiliations
(1) Department of Infection Control and Immunology, Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, Minato-ku, Tokyo, Japan
(2) Department of Kampo Pharmacy, Yokohama University of Pharmacy, Totsuka-ku, Yokohama-shi, Kanagawa, Japan
(3) Laboratory of Medical Microbiology, Graduate School of Pharmacy, Nihon University, Funabashi-shi, Chiba, Japan
(4) Nitto Pharmaceutical Industries, Ltd, Muko-shi, Kyoto, Japan
(5) Laboratory of Cell and Tissue Biology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
(6) Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, Minato-ku, Tokyo, Japan