Autoclaved Diet with Inactivated Spores of Bacillus spp. Decreased Reproductive Performance of Muc2−/− and Muc2+/− Mice

Abstract

Within barrier facilities, autoclaved diet and bedding are used for husbandry of laboratory rodents. Bacillus spp. are ubiquitous in nature and some of them are known as probiotics. Inactivation of the Bacillus spores and reduction of the diet nutritional value due to autoclavation could be especially critical for immunodeficient mice. We studied the effect of the autoclaved and non-autoclaved diets on the reproductive performance and the age of prolapse manifestation in Muc2−/− mice with impaired gut barrier function and, therefore, sensitive to change of microbiota. We found that the non-autoclaved diet led to enhancement of the fertility index of Muc2−/− and Muc2+/− female mice. The non-autoclaved diet affected the prolapse of Muc2−/− mice that occurred later in comparison with females eating the autoclaved diet. We showed that Bacillus spp. was present in the non-autoclaved diet and feces of mice on the non-autoclaved diet. Bacterial strains of the non-autoclaved diet and feces belonged to B. amyloliquefaciens, B. thuringiensis, B. subtilis, Lysinibacillus macrolides, B. cereus, and other representatives of Bacillus spp. Moreover, autoclavation of the diet affected on the percent of the blood and spleen immune cells, the bacterial composition of the intestine, and increased the level of methionine in the thigh muscle of mice. Enhanced reproductive performance and delayed prolapse manifestation in Muc2−/− mice could be due to improved digestion, as Bacillus spp. from diet and feces had enzymatic activity.

Normalization of Deviant Behavior in Muc2+/+ Mice through Dietary Incorporation of Bacillus subtilis Spores

“…Strains of the Bacillus spp. isolated from the nonautoclaved diet and mice feces were not resistant to kanamycin [41][42] . In this regard, it was possible to count the titer of B. subtilis BS20 that the mice received with diet [46] .…”

“…Bacillus spp. are present in laboratory diets for animals and can influence reproductive rates [41][42] . It was found that adding spores B. subtilis BS20 to the nonautoclaved diet had a higher effect on restoring normal behavior in Muc2 +/+ mice.…”

“…Since the bacteria Bacillus spp. are allochthonous, they are constantly present in small amounts in the diet of laboratory mice [41,42] . Since Bacillus spp.…”

Effect of the Bacillus subtilis BS20 on physiological and immune parameters in mutant mice Muc2–/–

“…Поскольку штамм B. subtilis BS20 стимулирует гуморальное звено иммунитета у мышей Muc2 -/-, возможно, это способствует развитию у них устойчивости к патогенным микроорганизмам и объясняет увеличение массы тела и продолжительности жизни. В предыдущих исследованиях показано, что мыши Muc2 -/при кормлении неавтоклавированным кормом, содержащим несколько видов представителей рода Bacillus, характеризовались лучшим репродуктивным индексом, более поздним появлением пролапса прямой кишки и высоким содержанием Т-хелперов в селезёнке, по сравнению с физиологическими и иммунологическими показателями мышей, получавших автоклавированный корм, содержащий инактивированные споры бактерий [26]. Добавление в корм штамма B. subtilis DE111 способствует увеличению уровня регуляторных Т-клеток и Т-хелперов, наряду со снижением содержания Т-киллеров [23].…”

Bacillus amyloliquefaciens: Harnessing Its Potential for Industrial, Medical, and Agricultural Applications—A Comprehensive Review

“…led to an increased incidence of intestinal inflammation due to alterations in the gut microbiome. Additionally, a decline in fertility was observed [ 62 ]. Table 2 provides a comprehensive overview of the medical and agricultural applications of B. amyloliquefaciens .…”