Lesaffre (France)

This study aimed to investigate the effects of temperature, illumination, and growth stage on the cell morphology, lipid content, and fatty acid (FA) composition in neutral lipids (NL) and polar lipids (PL) of Aurantiochytrium mangrovei, a thraustochytrid, widely known for its capacity to accumulate docosahexaenoic acid (22:6n-3, DHA). Experiments were conducted at three different temperatures (15°C, 20°C, and 25°C) under both illuminated and non-illuminated conditions. Illumination of the culture significantly increased OCFA (15:0 + 17:0) in PL by 42%, 6%, and 11% at 15°C, 20°C, and 25°C. Proportions of 15:0 + 17:0 in NL and PL increased with increasing temperature, being highest at 20°C in the exponential phase (7% in PL and 9% in NL) and at 25°C in the stationary phase (15% in PL and 32% in NL). The temperature also increased the DPAn-6 proportion during the exponential phase, from 2.5% to 5.9% in NL and from 5.5% to 11% in PL, whereas DHA (22:6n-3) tended to decrease. The resulting DHA/Docosapentaenoic acid (22:5n-6, DPAn-6) ratio in both NL and PL was highest in cultures at 15°C during the exponential phase. Cultivation of A. mangrovei at 15°C was favorable to a high DHA proportion (61% of total FA in PL and 68% in NL) and a high DHA/DPAn-6 (> 11 in PL and 23 in NL) ratio during the exponential phase. Further research is needed to better understand why DHA and DPAn-6, two very long-chain PUFA, are regulated in an opposite manner in response to changing temperature.

Abstract In recent years, beta-glucans (BG) have gained increasing attention for their diverse health-promoting properties in both humans and animals. Yeast beta-glucans are polysaccharides known for their immunomodulatory effects, which have been extensively studied in various animal models. Especially when they are coming from yeasts, these polysaccharides exhibit the ability to train the innate immune system in particular monocytes and macrophages, enhancing phagocytosis, cytokine production, and overall immune response. In livestock production, such as swine, supplementation with yeast beta-glucans has demonstrated significant improvements in growth performance, feed efficiency, and disease resistance. Our studies from the lab to the field have demonstrated the improvement of health parameters leading to improved performances of pigs fed with yeast β-1,3/1,6 glucan up to 4kg by the end of the fattening period. Additionally, a reduction in the incidence of infections such as Lawsonia intracellularis by 53% was measured in the group of pigs receiving yeast β-1,3/1,6 glucan. These results showed that beta glucans offer a good alternative to reduce reliance on antibiotics, thus enhancing sustainability in animal agriculture. Yeast beta-glucans offer a promising avenue for enhancing animal health and disease prevention in livestock production systems. Their multifaceted benefits, including immunomodulation and positive impact on microbiota, make them valuable additives in animal feed formulations, contributing to sustainable and resilient agricultural practices.

Background/Objectives: Post-menopausal women are at an increased risk of developing cardiovascular disease. Menaquinone-7 (MK-7) is a fat-soluble vitamin involved in coagulation and maintaining vascular health. The aim of the post hoc analysis of this one-year study is to investigate the effects of MK-7 supplementation on the vascular parameters in pre-, peri-, and post-menopausal women. Methods: In a clinical intervention trial (NCT02404519), a total of 165 women with a low vitamin K status received either 180 µg of MK-7 daily (n = 82) or a matching placebo (n = 83) for one year. Established vascular parameters were measured before and after one year of vitamin K2 supplementation. Pre-, peri-, and post-menopausal women were subdivided according to arterial stiffness, with a high b-stiffness index defined as being greater than the overall median of 9.83. Results: The post hoc analyses showed a significant decrease in desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) plasma levels after MK-7 supplementation (pre/peri, p = 0.009; post, p < 0.001). MK-7 treatment significantly attenuated vascular stiffness in post-menopausal women (placebo +49.1% ± 77.4; MK-7 +9.4% ± 67.1; p = 0.035). Post-menopausal women with a high stiffness index showed significantly improved vascular markers after MK-7 treatment, e.g., a decreased blood pressure at brachialis (-3.0% ± 9.0; p = 0.007) and an increased distensibility coefficient (+13.3% ± 32.3; p = 0.040). Conclusions: Our results confirm that menopause affects vascular health status. Post-menopausal women with an increased stiffness benefit most from MK-7 supplementation, with a significantly improved blood pressure. Further research is needed to unravel the beneficial effects of MK-7 in post-menopausal women.

Irritable bowel syndrome (IBS) is a multifactorial disorder of the gut-brain axis, characterized by visceral hypersensitivity (VH). Psychobiotics, through GABA synthesis, are good candidates to alleviate gastrointestinal discomfort. Here, we analyzed the GABA-producer Lactococcus lactis CNCM I-5388 as an active-enzyme postbiotic to relieve VH mediated by psychological stress. L. lactis CNCM I-5388 was inactivated by ethanol while maintaining its glutamate decarboxylase (GAD) activity. This EtOH-treated nonviable form was given daily orally for 1, 5, or 10 days to female Wistar rats in comparison with viable L. lactis CNCM I-5388 or vehicle. Visceral sensitivity was measured by electromyography before and after partial restraint stress (PRS). GABA was quantified in the stomach collected from rats and in the gastric compartment of TIM-1 human gut model in fed state. A daily treatment for 5 and 10 days by L. lactis CNCM I-5388 both in its viable and nonviable forms counteracted VH promoted by PRS. However, only viable L. lactis CNCM I-5388 tended to reduce VH after a single administration. After 5-day treatment, only under PRS conditions, the production of GABA within the stomach was enhanced in rats treated with viable or nonviable L. lactis CNCM I-5388. This increase was confirmed by using the TIM-1 human gut model. We found that a postbiotic with an active-GAD enzyme of L. lactis CNCM I-5388, similarly to its viable psychobiotic form, exerts anti-VH properties in an IBS-like rat model. These effects are associated with GABA production in the stomach where the low pH promotes GAD activity.

While RNA folding prediction remains challenging, even with machine and deep learning methods, it can also be approached from a topological mathematics perspective. The purpose of the present paper is to elucidate this problem for students and researchers in both the mathematical physics and biology fields, fostering interest in developing novel theoretical and applied solutions that could propel RNA research forward. With this intention, the mathematical method, based on matrix field theory, to compute the topological classification of RNA structures is reviewed. Similarly, McGenus, a computational software that exploits matrix field theory for topological and folding predictions, is examined. To further illustrate the outcomes of this mathematical approach, two types of analyses are performed: the prediction results from McGenus are compared with topological information extracted from experimentally-determined RNA structures, and the topology of RNA structures is investigated for biological significance, both in evolutionary and functional terms. Lastly, we advocate for more research efforts to be conducted at the intersection between physics, mathematics and biology, with a particular focus on the potential contributions that topology can make to the study of RNA folding and structure.

Lactic acid bacteria (LAB) and their exopolysaccharides (EPS) have the potential to enhance the quality of flour-based products. This study investigated the effect of EPS produced by Fructilactobacillus sanfranciscensis Ls5 on the quality of Mantou. LAB strains with high EPS production were isolated from traditional fermenters, and their characteristics and EPS properties were examined. Four different fermentation conditions (Blank, Yeast, Ls5-Yeast, and EPS-Yeast) were compared in terms of their effects on the physicochemical properties, in vitro digestion characteristics, and shelf-life of Mantou. The incorporation of Ls5 and its EPS into Mantou resulted in a lower dough fermentation pH, increased organic acid production, and enhanced fermentation activity. Additionally, the incorporation of Ls5 and its EPS led to significant improvements in the quality of the Mantou, including the extension of shelf-life, improved sensory evaluation, and a reduction in the sugar content. Additionally, there was an increase in resistant starch content during digestion in both types of Mantou, which could offer potential benefits to human glycemic health.

Thraustochytrids biomass, rich in docosahexaenoic acid (DHA), could be a sustainable ingredient for the aquafeed industry. However, its production cost renders it less competitive than fishmeal and fish oil from wild-caught fish. This study proposes optimizing the hydrolysis conditions of thraustochytrid biomass to generate an ingredient with improved properties thanks to the production of peptides with different biological activities. The improved nutritional value of the biomass could justify its use to decrease the amount of wild-caught fish in aquafeed, which would enhance the sustainability of fish aquaculture. First, two commercial proteases, Papain and Alcalase 2.4L, were compared for their capacity to hydrolyze the biomass. The best degree of hydrolysis (19 ± 1%) was obtained with Alcalase 2.4L, which was then used for the optimization of the pH, enzyme concentration and reaction time using response surface methodology. The results showed that the highest concentration of peptides and DHA in the aqueous phase was obtained with a pH, enzyme concentration and reaction time of 7.5, 2.7% and 205 min, respectively. If thraustochytrid hydrolysates prove to improve fish fitness, this mild and free-solvent process protocol could be used to produce a sustainable ingredient for aquafeed.