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months of life, reaching the state of mature microbiota when the child is around two years old. Even so, diet, lifestyle, antibiotic consumption or the aging process will determine changes in its composition and, as a consequence, the possibility of suffering chronic non-communicable diseases. Currently, there is sufficient scientific evidence to strengthen the importance of diet for the establishment, structure and functional activity of the gut microbiota, as well as many studies that demonstrate the role of diet in certain diseases through its effects on microbial communities of the gut. Modulation of the gut microbiota through dietary intervention is an emerging therapeutic and preventive strategy for many conditions. Probiotics and prebiotics may also be effective for restoration of beneficial bacteria and microbiota diversity capable to shift from disease to health promoting states. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dairy products have a potential positive impact on the management of T2DM. • Anti-diabetic properties of probiotics and prebiotics are based on multiple mechanisms. • Synbiotic products have better anti-diabetic properties than conventional dairy fermented foods. • New proposed prebiotics (non-carbohydrates and minerals) inside dairy matrices should be explored. • More clinical trials must be conducted to develop practice guidelines to control T2DM. Diabetes mellitus type 2 (T2DM) is associated with hyperglycemia, insulin resistance, and gut dysbiosis. Probiotics and prebiotics can ameliorate T2DM through different mechanisms of action, such as reducing oxidative stress, or the inhibition of pro-inflammatory markers, among others. Multiple studies in vitro and in vivo have demonstrated the reduction of hyperglycemia, depressive behaviors, obesity, oxidative stress, and insulin resistance in diabetic patients through the consumption of dairy products, such as yogurt, fermented milk, and cheese, enriched with potential probiotic strains, prebiotic ingredients, and synbiotics (understood as a combination of both). Therefore, this review aims to provide an updated overview about the impact of dairy foods with probiotics, prebiotics, or synbiotics to prevent and manage T2DM, the mechanism of action related to the host health, and the future tendencies for developing new dairy foods. Despite the addition of probiotics, prebiotics, and synbiotics to dairy products could be highly beneficial, more evidence, especially from clinical trials, is needed to develop evidence-based T2DM prevention guidelines. [ABSTRACT FROM AUTHOR]

Pectic oligosaccharides (POS) derived from industrial byproducts, such as lemon peels (LP) and sugar beet pulp (SBP), have been reported to be non-digestible oligosaccharides an catalogued as promising candidates as prebiotics. This work has evaluated the selective fermentation of POS by potential probiotic Lactobacillus and Bifidobacterium strains. POS were fully characterized based on molecular weight and proportion of neutral and acidic oligosaccharides. All the tested probiotic strains reached better growth results when SBP POS were added to the growth media than LP POS. On the other hand, while Lactobacillus rhamnosus GG showed poor growth with LP POS-2, Bifidobacterium lactis Bb-12 was the only strain able to ferment these compounds. Lactic, acetic and formic acids were the main organic acids derived from POS fermentation by the assayed strains. The cocultures with Bacteroides fragilis did not modify the fermentation capability of the probiotic bacteria. This study has demonstrated that complex POS derived from lemon and sugar beet byproducts could be used as carbohydrate source by lactobacilli and bifidobacteria, showing the low-molecular-weight LP POS-2 a specific bifidogenic effect towards B. lactis. Results are promising for the development of synbiotic supplements. • Pectic oligosaccharides (POS) from two industrial byproducts were used as substrates. • POS samples presented different composition and structural properties. • Growth of selected probiotic strains was promoted. • Maximum growth rates, optical densities and lag parameters were calculated. • The organic acids generation derived from POS fermentation was evaluated. [ABSTRACT FROM AUTHOR]

Abstract The potential of probiotic bacteria to produce prebiotic oligosaccharides by transgalactosylation has been minimally studied. In this work, we screened the β-galactosidase (β-gal) activity of dairy propionibacteria (PAB) isolated from Argentinean foods to select strains for the synthesis of oligosaccharides from lactose (GOS) and lactulose (OsLu). PAB, when grown in a medium with lactose as a carbon source, were disrupted, and the cell-free extracts were assayed for β-gal activity. Nine strains grew on lactose and showed β-gal activities from 0.27 to 2.60 U mL−1. Propionibacterium acidipropionici LET 120, the strain with the highest activity, was able to synthesize, using 30% lactose and lactulose at pH 6.5 and 45 °C, 26.8% of LET 120-GOS and 26.1% of LET 120-OsLu after 24 h. When they were tested as carbon sources for growth, P. acidipropionici LET 120 attained higher biomasses, μ max and β-gal activities at the expense of Aspergillus oryzae- OsLu, Vivinal®-GOS and lactulose compared to lactose or glucose. In addition, LET 120-GOS and LET 120-OsLu synthesized by PAB were prebiotic for some probiotic strains. For the first time, our results show the production of GOS and OsLu by dairy PAB, and these results encourage further studies on the optimization of the synthesis and structure characterization of the obtained oligosaccharides. Highlights • Dairy propionibacteria (PAB) exhibit highly variable β-galactosidase activity. • PAB LET-120 synthesizes oligosaccharides from lactose (GOS) and lactulose (OsLu). • LET-120 shows higher metabolic activity in OsLu, GOS and lactulose than in glucose. • GOS and OsLu from PAB supported the growth of some probiotic bacteria. [ABSTRACT FROM AUTHOR]

The microbiological and metabolic changes of an overweight-associated colonic microbiota after reducing in vitro the carbohydrate supply and its supplementation with oligosaccharides derived from lactulose (OsLu) were evaluated using a dynamic simulator of the gastrointestinal tract. The differentiation and stability of the microbial communities within each colon compartment were reached after two weeks of feeding the system with a high energy (HE) medium based on fructose and readily fermentable starches. The effect of reducing the energy content (low-energy medium, LE) and the supplementation with OsLu caused minor variations in bacterial counts, except for Enterobacteriaceae. The LE medium caused an effect on the microbial metabolic activity that was characterized by an absence of net butyrate production and an increase in ammonium content. This shift from fermentative to proteolytic metabolism was not observed when the LE medium was supplemented with OsLu. This oligosaccharide mixture was mainly metabolized in the proximal colonic compartment. The results obtained in this study indicate that the substitution in the diet of easily digestible carbohydrates by OsLu maintains the fermentative functionality of the intestinal microbiota, allowing the net production of butyric acid with potential beneficial effects on health, and avoiding a full transition to proteolytic metabolism profiles. [ABSTRACT FROM AUTHOR]

Abstract: The growth of potential probiotic strains from the genera Lactobacillus, Bifidobacterium and Streptococcus was evaluated with the novel lactose-derived trisaccharides 4′-galactosyl-kojibiose and lactulosucrose and the potential prebiotics lactosucrose and kojibiose. The novel oligosaccharides were synthesised from equimolar sucrose:lactose and sucrose:lactulose mixtures, respectively, using a Leuconostoc mesenteroides dextransucrase and purified by liquid chromatography. The growth of the strains using the purified carbohydrates as the sole carbon source was evaluated by recording the culture optical density and calculating maximum growth rates and lag phase parameters. The results revealed an apparent bifidogenic effect of lactulosucrose, being a moderate substrate for streptococci and not utilised by lactobacilli. In addition, 4′-galactosyl-kojibiose was selectively fermented by Bifidobacterium breve, which was the only tested bifidobacterial species able to ferment kojibiose. The described fermentation properties of the specific probiotic strains on the lactose-derived oligosaccharides would enable the design of prebiotics with a high degree of selectivity. [Copyright &y& Elsevier]

Abstract: The effect of structure on the fermentative properties of potential prebiotic trisaccharides derived from lactulose like 6′-galactosyl-lactulose (β-d-galactopyranosyl-(1→6)-β-d-galactopyranosyl-(1→4)-β-d-fructopyranose), 4′-galactosyl-lactulose (β-d-galactopyranosyl-(1→4)-β-d-galactopyranosyl-(1→4)-β-d-fructopyranose), and 1-galactosyl-lactulose (β-d-galactopyranosyl-(1→4)-β-d-fructopyranosyl-(1→1)-β-d-galactopyranose); and from lactose like 4′-galactosyl-lactose (β-d-galactopyranosyl-(1→4)-β-d-galactopyranosyl-(1→4)-β-d-glucopyranose) and 6′-galactosyl-lactose (β-d-galactopyranosyl-(1→6)-β-d-galactopyranosyl-(1→4)-β-d-glucopyranose), has been assessed in vitro. Fermentations with twelve pure strains of Lactobacillus, Streptococcus and Bifidobacterium were carried out using the purified trisaccharides as the sole carbon source, and bacteria growth was evaluated at 600nm by means of a microplate reader during 48h. Maximum growth rates (μmax) and lag phase were calculated. In general, all the strains tested were able to utilize lactulose and pure trisaccharides derived from lactulose and lactose when they were used as sole carbon source. Nonetheless, glycosidic linkage and/or the monosaccharide composition of the trisaccharides affected the individual strains lag phase, cell densities and growth rates. A general preference towards β-galactosyl residues β(1-6) and β(1-1) linked over those β(1-4) linked was observed, and some strains showed higher cell densities and speed of growth on 6′-galactosyl-lactulose than on 6′-galactosyl-lactose. This is the first study of the effect of lactulose-derived oligosaccharides on pure culture growth which shows that transglycosylation of lactulose allows for obtaining galactooligosaccharides with new glycosidic structures and would open new routes to the synthesis of compounds with potential prebiotic effects. [Copyright &y& Elsevier]