Spore-forming bacteria as probiotics
Recently, spore-forming probiotic bacteria have been highlighted by several companies marketing probiotic products. What are spore-formers and what are their benefits?
Most probiotics on the market consist of Lactobacilli and/or Bifidobacteria, including well-know strains such as Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12. Probiotic strains are typically selected based on their gastro-intestinal (GI) survival and shelf life, because those are the toughest challenges for the bacteria to survive. Contrary to Lactobacilli or Bifidobacteria, some bacterial species can form so called endospores. These are metabolically inactive cells with tough outer walls that can withstand extreme conditions and survive for even millions of years (1). This immediately shows one of the major benefits of spore-forming bacteria: they have excellent shelf life, can withstand high temperatures (sometimes spore-forming probiotics are even used in teas or cakes), and have excellent GI-survival. The endospores reactivate in the gut and can then exert their beneficial effects. In addition, these spore-formers are different bacterial genera and these probiotic species and strain have specific capabilities.
The most well-known and studied spore-forming species are Bacillus subtilis, B. coagulans, and B. clausii (1). The Microbiome Center collection contains well-studied strains of each of these species, such as B. subtilis R-179, B. coagulans Unique IS-2, and B. clausii UBBC-07. These strains have been studied for, among others, ulcerative colitis and SIBO (2, 3), constipation and IBS (4,5), and diarrhea and respiratory tract infections (6,7), respectively. Less well-known spore-forming probiotic bacteria include B. mesentericus and Clostridium butyricum, both of which are part of the Butyrate Generator building block. The latter species can produce butyrate, and this is one of the mechanism of actions that makes this building block having a strong anti-inflammatory effect and being effective for ulcerative colitis (8). In addition, it is expected that this is also why our own data-analyses have consistently found this building block to be effective for allergies, because allergies are linked to dysregulated immune responses and butyrate can modulate that.
Summarizing, there are several spore-forming probiotic species and the best-studied strains of all well-known Bacillus species, as well as some less common strains are available as building blocks at the Microbiome Center platform.
References:
- https://doi.org/10.3390/ijms23063405
- https://doi.org/10.12998/wjcc.v6.i15.961
- https://doi.org/10.1155/2020/4181748
- https://doi.org/10.1007/s12602-019-09542-9
- https://doi.org/10.3920/BM2017.0129
- https://doi.org/10.3920/BM2012.0034
- https://doi.org/10.2147/tcrm.2007.3.1.13
- https://doi.org/10.3748/wjg.v21.i19.5985