Effects of Inulin-Based Prebiotics Alone or in Combination with Probiotics on Human Gut Microbiota and Markers of Immune System: A Randomized, Double-Blind, Placebo-Controlled Study in Healthy Subjects

Abstract

The gut microbiota is implicated in diverse interactions affecting human health. The present study reports a randomized, double-blind, placebo-controlled clinical study conducted by administering a new synbiotic formulation composed of two Lactobacillus strains (L. plantarum and L. acidophilus) and one Bifidobacterium strain (B. animalis subsp. lactis) and two types of fructans (fructo-oligosaccharides with a degree of polymerization of 3–5 and inulin-type fructans with 10 DP). The effects of this synbiotic were evaluated on healthy subjects for 28 days and the maintenance of its efficacy was evaluated at the end of a follow-up period of 28 days. The synbiotic treatment contributes to higher biodiversity of the gut microbiota, increasing the community richness with respect to the group with the prebiotics alone and the placebo group. Its positive effect is also reflected in the variation of microbial community structure favoring the beneficial short-chain fatty acids bacterial producers. The amelioration of the health status of the subjects was also established by the reduction of common infectious disease symptom incidence, the stimulation of the gut immune system showing a noteworthy variation of fecal β-defensin2 and calprotectin levels, and the modulation of the response of the respiratory tract’s immune system by salivary IgA as well as total antioxidant capacity biomarkers.

Positive modulation of a new reconstructed human gut microbiota by Maitake extract helpfully boosts the intestinal environment in vitro

“…The in vitro HGM was conceived considering E. coli, B. cellulosilyticus, F. plautii, and C. symbiosum as members of the minimal core (Table 2) because they belong to Pseudomonadota, Bacteroidota, and Bacillota phyla, respectively. The selected set-up embraces what is currently known about the composition of the gut microbiota in vivo thanks to the numerous published papers regarding clinical trials and reconstructed gut communities [8,27,38]. Both Eckburg et al [47] and Vaga et al [48] analyzed mucosal and fecal samples obtained from healthy subjects.…”

“…Total DNA was extracted from single bacterial cultures (title of around 10 8 CFU/mL) for the construction of standard curve to quantify the strains by qPCR analyses [ 37 , 38 ]. Total DNA was obtained by Ultraclean Microbial DNA Isolation Kit (Qiagen, Milano, Italy).…”

“…The total DNA of the three tested conditions in batch fermentations was extracted using Stool Nucleic Acid Isolation Kit (Norgen Biotek Corp., Thorold, Canada) following the protocol provided by the manufacturer with some modifications [ 38 ].…”

“…Different qPCR programs were employed. For DNA amplification of LP, LA, BL, BC, CO, and EC strains the program was of 40 cycles of 15 seconds at 95°C and 1 minute at 60°C [ 38 ]; for CS, 40 cycles of 5 seconds at 95°C, and 30 seconds at 60°C (adapted from Ogita et al [ 43 ]). Each DNA sample was analyzed in triplicate.…”

Synergistic Antioxidant Effect of Prebiotic Ginseng Berries Extract and Probiotic Strains on Healthy and Tumoral Colorectal Cell Lines

“…Though, oxidative stress could be prevented and balanced through antioxidant defense systems, which comprehend bioactive compounds of different origins, both endogenous (human enzymes) and exogenous (bacteria and natural molecules) [3]. In the last category, functional foods mixing both specific probiotic bacterial strains and natural extracts are emerging as a real solution due to proven health benefits for immune system, intestinal microbiota, and brain through the gut-brain connection [2,[4][5][6][7]. Indeed, among the probiotic features is counted the strain-dependent antioxidative ability.…”