Spore Formers as Beneficial Microbes for Humans and Animals

Abstract

Microorganisms efficiently colonize the external and internal surfaces of the animal body establishing mutually beneficial interactions and forming site- and individual-specific microbiota. The degradation of complex polysaccharides in the animal gut, the production of useful compounds, protection against pathogenic microorganisms and contribution to the development of an efficient immune system are the main beneficial effects of a balanced microbiota. A dysbiosis, an imbalanced composition of the microbiota, has been associated with a large number of diseases from gastro-intestinal or urogenital disorders to allergies, cardiovascular and autoimmune diseases and even to the onset of certain cancers. A growing body of evidence has indicated that probiotic treatments, aimed at maintaining or rebalancing the microbiota, are useful to treat/prevent those illnesses. Lactic Acid Bacteria and Bifidobacteria are the most common microbes used in probiotic preparations; however, other bacteria and yeast cells are also widely used in commercial products. Here we focus on the use of bacterial spore formers as probiotics. Spore formers have been marketed as probiotics for over 50 years and are now extensively used for the treatment of intestinal disorders and as dietary supplements in humans, as growth promoters and competitive exclusion agents in animals.

Sporulation efficiency and spore quality in a human intestinal isolate of Bacillus cereus

“…A panel of relevant antibiotics was used to assess the susceptibility of MV19 cells. As reported in Table 2, MV19 cells showed MIC for vancomycin higher than the breakpoint levels indicated for members of the Bacillus genus (Saggese et al 2021) and a weak resistance to streptomycyn and chloramphenicol (Table 2).…”

Comparative Genomics and Physiological Characterization of Two Aerobic Spore Formers Isolated from Human Ileal Samples

“…SF106 and SF174 were then classified as strains of the B. subtilis and A. clausii species, respectively. This is an important point, since both these two species are in the qualified presumption of safety (QPS) list of the EFSA ( , accessed on 1 April 2022) and several strains belonging to them are widely marketed as probiotics for human and animal use [ 4 , 6 ].…”

“…Aerobic spore formers of the Bacillus genus have long been considered soil bacteria and, indeed, are abundant inhabitants of wet and dry soils and of plant rhizospheres. However, they are also abundantly present in the gut of insects and animals, where they enter as spores with food and water [ 4 , 5 , 6 ]. In mammals, spores safely transit the stomach and some of them germinate in the intestine, favored by the mildly acidic pH and by the abundance of nutrients [ 7 ].…”

Modulation of intestinal epithelial cell proliferation and apoptosis by Lactobacillus gasseri SF1183

“…Well-known examples in this context are lactic acid bacteria, present in a variety of traditional fermented foods 7 and spore formers of the Bacillus genus found in Natto, a Japanese traditional healthy food based on soybeans fermented with the B. subtilis var. natto and in similar fermented foods traditionally used in various countries 8 . Several species of the Bifidobacterium, Lactobacillus, Bacillus and Saccharomyces genera have long been used as commercial probiotics 8,9 .…”

“…natto and in similar fermented foods traditionally used in various countries 8 . Several species of the Bifidobacterium, Lactobacillus, Bacillus and Saccharomyces genera have long been used as commercial probiotics 8,9 . In addition, other intestinal bacteria have been proposed as nextgeneration probiotics, such as Faecalibacterium prausnitzii 10 and Akkermansia muciniphila 11 .…”