The potential anti-inflammatory activity of probiotics Lactobacillus spp. e Rhodopseudomonas palustris is the subject of a recently published scientific study on Bioactive Compounds in Health and Disease (Tjie Kok, 2023) which confirms the vital role of these microorganisms in human health. (1)
1) Probiotics, introduction
The concept of 'probiotic' (from the Greek 'pró bíos', προς βίος', favorable to life) was introduced in 1908 by Nobel laureate Ilya Metchnikoff, who developed the theory of a correlation between the longevity of nomadic tribes in Bulgaria and Russia and their regular consumption of fermented milk. The most current definition of 'probiotics' – 'live microorganisms that, when administered in adequate amounts, confer a health benefit on the host' – was elaborated by the panel of experts gathered in 2013 by the International Scientific Association for Probiotics and Prebiotics (ISAPP). (2)
The bacteria they are classified as probiotics when they possess specific characteristics and properties. In particular, when they:
– are usually present in the intestinal microbiome,
– resist the digestive action of intestinal enzymes, bile salts and gastric juice,
– do not cause negative immune reactions,
– adhere to intestinal cells and colonize them,
– exert beneficial effects on human health, through antagonistic action against pathogenic microorganisms and production of antimicrobial substances.
in the field of probiotics has aroused growing interest in biology and medicine, with focus both on bacterial strains of lactic fermentation (e.g. Lactobacillus spp..), and on microorganisms present in the intestinal bacterial flora (eg. Bifidobacterium).
1.1) Probiotics, the health benefits
Probiotics they have proven effective in the prevention and treatment of various pathologies, thanks to their role in inhibiting the proliferation of pathogens in the intestine. The numerous health benefits associated with their consumption have so far been associated, in particular, with the mechanisms of:
• competition for nutrients and sites of adhesion to the walls of the intestine,
• reduction of faecal pH and acidification of the intestinal environment,
• production of nutrients for intestinal cells,
• reduction of blood cholesterol levels,
• possible prevention of food allergies.
Studies on microbiome, microbiota and holobiont (the host plus of all its microbial symbionts, including transient and stable members) are indeed offering a new perspective on human and animal health (3,4). And these microorganisms, as well as some bioactive compounds, express a potential of great interest. (5)
2) Inflammation, an immune response
Inflammation it is a set of events of a reactive nature, which takes place in the tissues when they come into contact with harmful agents of various kinds:
– physical (e.g. trauma, radiation, high or low temperatures, etc.),
– chemistry (e.g. various chemicals, poisons and toxins), e
– biological (infectious agents).
This process pathophysiological it therefore constitutes a fundamental immune response to harmful stimuli, with the task of neutralizing the harmful agent or delimiting the lesion it produces.
Excessive inflammation however, it can trigger or contribute to the development of numerous pathologies. Macrophages, the fundamental cell population in the immune system, are in fact activated by pro-inflammatory cytokines to engulf bacteria and other foreign particles. And therefore they play a key role in the inflammatory process.
3) Probiotics, modulation of the immune system and inflammation
The properties of probiotics to modulate the immune system, according to the hypothesis formulated by Professor Tjie Kok, may also have a potential in modulating inflammation. In fact, probiotics – resistant to the action of gastric juice and biliary secretion – adhere to the epithelial cells in the intestine and counteract the action of some pathogenic germs. With a favorable impact on the health of the intestinal microbiota and a possible positive influence on the immune system.
A systematic review under examination (Kok, 2023) therefore proposes to investigate in detail the anti-inflammatory effects of probiotics Lactobacillus spp. e Rhodopseudomonas palustris on macrophage cells RAW 264.7.
The probiotic extract was divided into extract and cells, through a centrifugation. Next, RAW 264.7 macrophage cells were exposed to lipopolysaccharide (LPS) to stimulate an inflammatory response. And the probiotic extract was added to the cells, to evaluate its effects on cell viability and cytokine expression. Cell viability was determined by the MTS assay. The levels of proinflammatory cytokines (IFN-γ, IL-1β, TNF-α, IL-8, TGF-β1) and anti-inflammatory antibody (IL-10) were measured by ELISA and qRT-PCR assays.
THEinput of probiotic extract, up to 1% v/v, has been shown to maintain cell viability over 80%, thus suggesting safety for cells. Induction of inflammation by LPS led to elevation of proinflammatory cytokines and reduction of IL-10. Treatment with the 0,03% v/v probiotic extract significantly reduced the levels of IFN-γ, IL-1β, TNF-α, IL-8 and TGF-β1, while simultaneously increasing the expression of the IL-10 mRNA.
The synergistic interaction between Lactobacillus spp. e Rhodopseudomonas palustris, within the probiotic blend, may have contributed to the production of bioactive compounds, including metabolites with anti-inflammatory properties. LPS induction triggered the increase of proinflammatory cytokines, consistent with previous studies. And treatment with the probiotic extract actually mitigated that response by reducing the levels of these cytokines and enhancing the expression of IL-10 (a cytokine with known anti-inflammatory properties).
The reduction of IFN-γ and TNF-α suggests that the extract may suppress the pro-inflammatory response, offering new possibilities for addressing inflammation-related disorders. The decrease in IL-8 and TGF-β1 indeed demonstrates the ability of the extract to modulate inflammatory signaling pathways. And the increase in IL-10 expression reflects the extract's ability to create an anti-inflammatory microenvironment.
4) Potential anti-inflammatory activity of Lactobacillus spp.. and Rhodopseudomonas palustris. Provisional conclusions
The anti-inflammatory potential of probiotics, already suggested in previous studies (6,7), finds further confirmation in the research in question (Kok, 2023). The probiotic extract of Lactobacillus spp. e Rhodopseudomonas palustris has been shown to effectively modulate cytokine expression, promoting an anti-inflammatory profile. These results open new avenues for the use of these probiotics in strategies aimed at managing chronic inflammatory diseases. In addition to suggesting the opportunity for the development of functional foods and food supplements with anti-inflammatory action.
Gabriele Sapienza and Dario Dongo
(1) Tjie Kok. Anti-inflammatory activity of Lactobacillus Spp. and Rhodopseudomonas Palustris probiotics. Bioactive Compounds in Health and Disease (BCHD), Vol. 6, no. 4, 20 Apr. 2023, p. 63. DOI: 10.31989/bchd.v6i4.1067
(2) Colin Hill, Francisco Guarner, Gregor Reid Glenn R. Gibson, Daniel J. Merenstein, Bruno Pot, Lorenzo Morelli, Roberto Berni Canani, Harry J. Flint, Seppo Salminen, Philip C. Calder & Mary Ellen Sanders. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol 11, 506-514 (2014). https://doi.org/10.1038/nrgastro.2014.66
(3) Paola Palestini, Dario Dongo. Microbiome and intestine, the second brain. GIFT (Great Italian Food Trade).
(4) Dario Dongo, Andrea Adelmo Della Penna. Animal husbandry, algae and microalgae to prevent the use of antibiotics. Algatan. GIFT (Great Italian Food Trade).
(5) Dario Dongo, Carlotta Suardi. More probiotics, less antibiotics. GIFT (Great Italian Food Trade).
(6) Vittorio Bottazzi. Fermented, functional and probiotic milks (Elite Communication, 2004) https://tinyurl.com/4wakrcvm
(7) Giulia Pietrollini. Probiotics, a solution for chronic inflammation. GIFT (Great Italian Food Trade).