Caroline Perreau

Background and objectives: The average intake of dietary fibers known to beneficially modulate the gut microbiota is below recommendations in high-income countries. This study aimed to evaluate the gut effects of resistant dextrin in healthy male adults with normal weight, consuming high (≥ 25 g/day; HF) or low (≤15 g/day; LF) levels of fiber as part of their usual diet. Methods: In this randomized, double-blind, placebo-controlled trial, participants received either 15 g/day of resistant dextrin (NUTRIOSE ^® soluble fiber) or a placebo (maltodextrin) for 4 weeks. Gut microbiota composition, and especially the relative abundance of the Parabacteroides genus, gut microbiota function, fecal parameters [pH, short chain fatty acids (SCFAs) and secretory IgA], and stool frequency and consistency, were assessed. Results: Overall, 124 subjects were recruited, 62 in each treatment arm; 57 in HF, 67 in LF; age: 36.2 ± 11.6 years. The mean relative abundance of Parabacteroides at baseline was similar in the LF (1.5%) and HF (1.3%) subgroups. It increased with the active supplementation and remained stable with the placebo, both in the entire population (5.5% vs. 1.4%; p < 0.0001) and in the subgroups of dietary fiber intake (HF: 5.5% vs. 1.5%; LF: 5.5% vs. 1.3%; p < 0.0001), then returned to baseline levels 2 weeks later. Among Parabacteroides , P. distasonis showed the highest abundance in the active arm as compared to placebo (2.6% vs. 0.5%; p < 0.0001). The Bacillota phylum was less abundant (tendency) at the end of intervention (55.4% vs. 59.0%; p = 0.0545). Conversely, several species from the Clostridium genus were more abundant. From a functional perspective, resistant dextrin intake tended to increase bacterial genes involved in α- and β-glucosidase activities, and to decrease those involved in propionate production, especially in the HF subgroup. No treatment effect ( p > 0.05) was found on pH, SCFAs, IgA, stool consistency and frequency. Conclusion: The tested resistant dextrin was effective in modulating the gut microbiota after four weeks of supplementation in healthy male volunteers, favoring the Parabacteroides genus and several related species (especially P. distasonis ). The treatment effect was observed in both subgroups of dietary fiber intake, and was even more pronounced in the high-intake subgroup. Clinical trial registration: https://clinicaltrials.gov/ , identifier NCT05105425.

Pectin comprises homogalacturonan (HG) and rhamnogalacturonan-I (RG-I). High molecular weight (Mw) pectin can be hydrolyzed into smaller pectic polysaccharides (PPS), offering different solubility and viscosity.We investigated how structural differences influence the bioactivity of potato-derived PPS fractions. Direct immunomodulatory effects were evaluated using a Caco-2/PBMC coculture model, while indirect, microbiome-mediated effects were evaluated via ex vivo colonic fermentation using the ex vivo SIFR® technology, coupled to the same immune model.Both PPS fractions were enriched in RG-I, in contrast to apple pectin, which was HG-rich and characterized by higher galacturonic acid and lower galactose content. High Mw PPS exhibited higher acetylation, whereas low Mw PPS showed more galactan branching. Both PPS fractions induced moderate cytokine responses under basal conditions (healthy state), while attenuating LPS-induced secretion of pro-inflammatory cytokines, effect likely related to their low degree of methyl-esterification. Both PPS fractions were utilized by gut microbes, resulting in increased short-chain fatty acid (SCFA) production and selective enrichment of beneficial taxa. PPS elicited stronger bifidogenic effects than apple pectin. Fermentation-mediated immunomodulatory effects mirrored those of the non-fermented compounds.PPS distinctly shaped the gut microbiome and host immunity depending on their structural features, supporting a structure-guided approach for selecting health targeting ingredients.

Increasing protein content of foods is effective in reducing postprandial hyperglycaemia, but animal protein may exacerbate insulin sensitivity. This single-blind, randomised, crossover study compared the effects of co-ingesting glucose with 10 or 20 g whey protein and glucose with 10 or 20 g pea protein, with a reference product (glucose) on glycaemic and insulinaemic responses in 30 healthy individuals. Blood glucose and plasma insulin were measured at baseline, 15, 30, 45, 60, 90, 120, 150 and 180 minutes after product consumption. The trial was registered with Clinical Trials.gov (NCT04871971). Glucose incremental area under the curve (mmol/l*min) at 180 minutes was significantly reduced (p < 0.001) for glucose with 20 g pea protein (89.8 ± 51.6) and glucose with 20g whey protein (98.5 ± 58.0) compared to glucose (143.2 ± 74.0). Insulin incremental area under the curve at 180 minutes (µU/ml*min) for glucose with 20 g pea protein (4304.56 ± 1896.07) was significantly lower (p < 0.001) than glucose with 20g whey protein (6311.81 ± 3489.12). This study has shown a superior effect of pea protein over whey protein in reducing glycaemic response, without any excessive increase in insulinaemic response.

As older adults tend to reduce their intake of animal-source proteins, plant-source proteins may offer valuable resources for better protein intake. The aim of this study was to assess whether the pea proteins can be used to achieve blood amino acid levels that stimulate muscle protein synthesis. We measured variations in plasma amino acid concentrations in young and older adults given pea (NUTRALYS^® S85 Plus) or whey proteins either alone or in a standardized meal. The effect of amino acid concentrations on protein synthesis in C2C12 myotubes was determined. In terms of results, plasma amino acid concentrations reflected the difference between the amino acid contents of whey and pea proteins. Blood leucine showed a greater increase of 91 to 130% with whey protein compared to pea protein, while the opposite was observed for arginine (A greater increase of 147 to 210% with pea compared to whey). Culture media prepared with plasmas from the human study induced age-dependent but not protein-type-dependent changes in myotube protein synthesis. In conclusion, pea and whey proteins have the same qualities in terms of their properties to maintain muscle protein synthesis. Pea proteins can be recommended for older people who do not consume enough animal-source proteins.

Animal-sourced whey protein (WPr) is the most popular protein supplement among consumers and has been shown to improve muscle mass and strength. However, due to allergies, dietary restrictions/personal choices, and growing demand, alternative protein sources are warranted. Sedentary adults were randomized to pea protein (PPr) or WPr in combination with a weekly resistance training program for 84 days. Changes in whole-body muscle strength (WBMS) including handgrip, lower body, and upper body strength, body composition, and product perception were assessed. The safety outcomes included adverse events, vital signs, clinical chemistry, and hematology. There were no significant differences in the change in WBMS, muscle mass, or product perception and likability scores between the PPr and WPr groups. The participants supplemented with PPr had a 16.1% improvement in WBMS following 84 days of supplementation (p = 0.01), while those taking WPr had an improvement of 11.1% (p = 0.06). Both study products were safe and well-tolerated in the enrolled population. Eighty-four days of PPr supplementation resulted in improvements in strength and muscle mass comparable to WPr when combined with a resistance training program in a population of healthy sedentary adults. PPr may be considered as a viable alternative to animal-sourced WPr without sacrificing muscular gains and product enjoyment.

Background and Objectives: Positive impacts of sugar-free chewing-gum (SFCG) were largely described in the literature. In addition to the increase in salivary flow and the mechanic effect of CG, their main ingredient, i.e., polyols, can also have some specific benefits on oral health on their own. Some have been shown to have a bacteriostatic effect on acid-producing bacteria, and others have been shown to be particularly active on dental plaque early colonizers, resulting in both a reduction in dental caries prevalence or a decrease in gums inflammation. Here, we aimed to demonstrate these positive effects using the tablet vector only composed of compressed polyols. Methods: We used a customized inversed pH-telemetry test that is often used to demonstrate the “safe for teeth” characteristics of a food product. This inversed pH-telemetry test was designed to evaluate the potential of a food product to counteract the dental plaque drop in pH following a sucrose challenge, according to the regulatory advised test. It was performed on five healthy volunteers that grew 5-day dental plaque over a micro electrode to measure their pH in situ. Three different tablets were tested: 100% maltitol versus 100% sorbitol versus control tablets (70% starch + 30% resistant dextrin). Results: For each tablet, a neutralization score was calculated as the difference in the pH values (pH values at the end of the consumption of the respective tablets—pH value just before consumption of the tablets). Positive values indicate a neutralization (increase in pH during the consumption of the product), meaning that the neutralization with maltitol tablets was the greatest among tested tablets (p = 0.003 vs. control). Sorbitol tablets also had a significant impact (p = 0.01 vs. control). Discussion/Conclusions: This inversed pH-telemetry was designed to show a neutralizing effect of polyol tablets as it has been conducted with sugar-free chewing-gums. We demonstrated here that tablets were also able to counteract the dental plaque pH drop induced by a sucrose challenge, showing clearly that tablets should also be considered as oral health beneficial products. Consequently, the consumption of polyols in various vectors should be regulatory, as is recommended for SFCG.

The objectives of the present research were to investigate (1) the nutritional quality through the Protein Digestibility-Corrected Amino Acid Score (PDCAAS); (2) the apparent viscosity under simulated in vitro gastric conditions of two pea protein isolates named NUTRALYS^® pea protein and NUTRALYS^® S85 Plus. In the first study, the in vivo protein digestibility was measured according to the methodology recommended by the FAO/WHO in 1991. Growing rats were fed a diet containing 10% proteins or a protein-free diet during a minimum of a 5-day balance period with daily collection of faeces. The true digestibility was measured using the rats’ nitrogen intake and fecal nitrogen. PDCAAS was calculated using the amino acid profile and the protein digestibility. In the second study, in vitro gastric digestion was simulated using the NIZO SIMPHYD model. The profiles of “fast-” or “slow-digested” proteins were evaluated and compared to whey and casein proteins by measuring the evolution of the viscosity in these conditions. Both of the tested proteins displayed a balanced amino acid profile with high concentrations of arginine, branched-chain amino acids, lysine and glutamic acid. The true protein digestibility of NUTRALYS^® pea protein and NUTRALYS^® S85 Plus were 97% ± 2 and 96% ± 3, respectively. According to the FAO/WHO requirement profile (2007) mainly used in Europe for adults or the profile from 1991 mainly used in the United States for all age groups except infants, the PDCAAS results of NUTRALYS^® pea protein were 93 and 81, respectively. The PDCAAS scores of NUTRALYS^® S85 Plus were 92 and 81, respectively (Study 1). The digestion of NUTRALYS^® pea protein resulted in a clear increase in viscosity during the gastric acidification and a sudden drop in viscosity after the addition of the gastric enzymes. The viscosity profile of NUTRALYS^® S85 Plus did not change during digestion (Study 2). The range of pea proteins evaluated in these studies displayed a high nutritional quality profile. NUTRALYS^® pea protein is an “intermediate-fast protein” and NUTRALYS^® S85 Plus is a “fast-digested protein”, meaning that these ingredients can be adapted to specific nutritional needs. These results show that plant-based proteins, like those of the NUTRALYS^® range, may allow us to design high-quality protein.

Background and Objectives: Excessive deposits of white adipose tissue lead to obesity. Preadipocyte differentiation, adipocyte metabolism, and some inflammatory and profibrotic factors are key in modulating early fat mass expansion and chronic low-grade inflammation and could be targeted to prevent child obesity. Plant-based proteins are being increasingly used, and we evaluated the potential impact on adipose cell biology and the inflammatory processes of some of them, after simulated in vitro gastrointestinal digestion, on (1) the human preadipocyte differentiation, (2) their fibro-inflammatory state, (3) the metabolism of human mature adipocytes, and (4) the beiging potential of two selected digestates on preadipocytes. Methods: (a) Preadipocytes and (b) mature adipocytes isolated from human subcutaneous adipose tissues were treated with eight plant-based protein digestates (PBPDs) and one animal-based protein digestate for (a) 7 to 11 days or (b) 24 h, respectively. We assessed (a) their effects on preadipocytes, in proadipogenic ± proinflammatory conditions, by evaluating cytotoxicity, cell number, lipid droplet accumulation, adiponectin secretion, and UCP1 expression on the one hand, and IL6, CCL2, and fibronectin secretions on the other hand, and (b) their effects on adipocyte metabolism by studying cytotoxicity, lipolysis activity, and adiponectin secretion. Results: Six PBPDs stimulated adiponectin’s secretion by the preadipocytes without affecting their viability and differentiation capacities at the tested doses. Similarly, we observed no cytotoxicity effects on mature adipocytes and a dose-dependent increase in their adiponectin secretion for treatment with five PBPDs. One PBPD modulated the lipolytic activity of adipocytes by decreasing the release of glycerol. In proinflammatory conditions, seven PBPDs reduced the number of preadipocytes, which is abnormally increased with inflammation. Two of them were able to decrease the CCL2 chemokine secretion, and one of them reduced the production of fibronectin, a potential pro-fibrotic protein. Finally, two selected PBPDs were able to increase beige differentiation (UCP1 expression) of preadipocytes cultured in proadipogenic conditions. Discussion: This study revealed potential benefits of plant proteins for obesity prevention, and specifically highlighted the respective properties of pea and oat proteins prototypes: increasing adiponectin secretion and beige differentiation in preadipocytes; decreasing pro-inflammatory and fibrotic molecules secretion by proinflammatory preadipocytes and regulating basal lipolysis and increasing adiponectin secretion by mature adipocytes.

NUTRIOSE^® (Roquette, Lestrem, France) is a resistant dextrin with well-established prebiotic effects. This study evaluated the indirect effects of pre-digested NUTRIOSE^® on host immune response and gut barrier integrity. Fecal samples from eight healthy donors were inoculated in a Colon-on-a-plate^® system (ProDigest, Ghent, Belgium) with or without NUTRIOSE^® supplementation. Following 48 h fermentation, colonic suspensions were tested in a Caco-2/THP1-Blue™ co-culture system to determine their effects on gut barrier activity (transepithelial electrical resistance) and immune response following lipopolysaccharide stimulation. Additionally, changes in short-chain fatty acid levels (SCFA) and microbial community composition following a 48 h fermentation in the Colon-on-a-plate^® system were measured. Across all donors, immune-mediated intestinal barrier damage was significantly reduced with NUTRIOSE^®-supplemented colonic suspensions versus blank. Additionally, IL-6 and IL-10 levels were significantly increased, and the level of the neutrophil chemoattractant IL-8 was significantly decreased with NUTRIOSE^®-supplemented colonic suspensions versus blank in the co-culture models following lipopolysaccharide stimulation. These beneficial effects of NUTRIOSE^® supplementation were likely due to increased acetate and propionate levels and the enrichment of SCFA-producing bacteria. NUTRIOSE^® was well fermented by the colonic bacteria of all eight donors and had protective effects on inflammation-induced disruption of the intestinal epithelial barrier and strong anti-inflammatory effects.