Biohydrogenation of Linoleic Acid by Lactic Acid Bacteria for the Production of Functional Cultured Dairy Products: A Review

Lactobacillus acidophilus (strain Scav) postbiotic metabolites reduce infection and modulate inflammation in an in vivo model of Pseudomonas aeruginosa wound infection

AIMS

This study assessed the antibacterial, antibiofilm, and immunomodulatory activity of Lactobacillus acidophilus (strain Scav) postbiotic (LaP) in a mouse model of Pseudomonas aeruginosa wound infection and evaluated the bioactive components of the LaP.

METHODS AND RESULTS

LaP was tested for Pseudomonas aeruginosa clearance and immunomodulatory activity during wound infection. We show that LaP applied 1 h after infection reduced tissue bacterial burden within 24 h, and this reduction persisted for 5 days. Ciprofloxacin given once at the exact same time did not reduce bacteria load as compared to vehicle controls. LaP reduced plasma IL-6 and MCP-1 levels after 5 days. Wound tissue IL-6 and MCP-1 levels were increased in infected vehicle mice at 5 days, but tissues from LaP-treated mice were similar to sham controls. LaP increased tissue IL-10 (antiinflammatory cytokine) levels. Ciprofloxacin decreased plasma and tissue IL-6 compared to vehicle controls but did not affect MCP-1 or IL-10 levels. To elucidate antibacterial and antibiofilm metabolite(s) in LaP, fractionation followed by Ps. aeruginosa antagonistic activity assays were performed. This was followed by liquid chromatography coupled to mass spectrometry (LCMS) analysis. Our analyses identified a low molecular weight, polar molecule, which had both antibacterial and antibiofilm activity.

CONCLUSIONS

Lactobacillus acidophilus secretes an antibacterial and antibiofilm metabolite that reduced pathogen burden and resolved systemic inflammation in a Pseudomonas aeruginosa wound infection model.

Loss of Myostatin leads to low production of CH4 by altering rumen microbiota and metabolome in cattle

Myostatin (MSTN) is a protein that plays a crucial role in regulating skeletal muscle development. Despite the known benefits of MSTN mutant cattle for increasing beef production, their potential impact on CH4 emissions has not been quantified. The study comparing wild-type (WT) cattle to MSTN-knockout (MSTN-KO) cattle revealed that CH4 production was lower. Macrogenomic analysis revealed a significant decrease in rumen archaea, with reduced Richness indices (P = 0.036). The MSTN-KO cattle also showed altered archaea distribution and composition at different taxonomic levels. LEfSe results showed changes in 21 methanogenic archaea clades, with obligately hydrogen (H2)-dependent methylotrophs Candidatus Methanoplasma termitum species belonging to Methanomassiliicoccales order demonstrating the most significant decrease. Rumen metabolites revealed a decrease in the ratio of acetate to propionate, indicating a shift in rumen fermentation pattern towards propionate fermentation. Additionally, the changing trend of methanogenic archaea is consistent with the evolution of methanogens, and this is correlated with the higher levels of linoleic acid in the rumen of MSTN-KO cattle. Linoleic acid affects the utilization of H2 by methanogenic archaea, leading to a reduction in obligately H2-dependent methylotrophs. Our study suggests that MSTN-KO cattle have potential as an economically and ecologically benign breed for reducing methane emissions.

Conjugated Linoleic Acid in Cancer Therapy

Conjugated Linoleic Acid (CLA) is a polyunsaturated dietary fatty acid. Probiotics can biohydrogenate CLA with multiple health benefits, especially in cancer treatment. In vitro, in vivo, and clinical studies have confirmed CLA isomers to possess anti-cancer activity. CLA has demonstrated its potential as an alternative treatment for cancer and also used as an adjuvant to reduce the side effects of existing treatment methods. The mechanism of the anticancer activity of CLA is still not clear; however, it may involve intervention with the cell cycle and modulation of gene expression. A greater potential of CLA for cancer treatment has been supported by more and more clinical trials to evaluate its potential. Some advanced technologies are in progress to overcome the flaws of current methods and enhance the microbial production of CLA. In conclusion, nutritional enrichment as a functional food and direct consumption of CLA may contribute to cancer management.

Soybean oil and probiotics improve meat quality, conjugated linoleic acid concentration, and nutritional quality indicators of goats

This study aimed to investigate the impact of dietary soybean oil and probiotics on goat meat quality, total conjugated linoleic acids (TCLA) concentration, and nutritional quality indicators of goats. Thirty-six male crossbred goats (Anglo-Nubian♂× Thai native♀), weighing 18.3 ± 2.7 kg, were selected and randomly assigned to six groups in a 2 × 3 factorial design, with six replicates per group. The soybean oil supplementation levels were 25 and 50 g/kg, while the probiotic supplementation levels were 0, 2.5, and 5.0 g/h/day. The results showed that supplementing the diet with 50 g/kg soybean oil significantly improved the average daily gain (ADG) (p = 0.02) and carcass yield (p = 0.05), while reducing the feed conversion ratio (p = 0.05). Additionally, the addition of 2.5 g/h/day of probiotics significantly increased dry matter intake (p(L) = 0.05, p(Q) = 0.03). Notably, supplementation with 50 g/kg soybean oil reduced the Warner-Bratzler shear force (p = 0.05) and a* (p = 0.01) values of the Longissimus thoracis et lumborum. However, 2.5 g/h/day of probiotics significantly improved (p(L) = 0.01, p(Q) = 0.04) the a* value of Longissimus thoracis et lumborum. Soybean oil supplementation at 50 g/kg increased the ether extract composition of Biceps brachii (p = 0.05) and Semimembranosus (p = 0.05). Additionally, it significantly increased TCLA content (p < 0.01) and reduced the n-6/n-3 ratio (p < 0.01). Interestingly, the supplementation of 5.0 g/h/day probiotics significantly reduced the thrombogenic index (p = 0.03). Moreover, supplementing with 50 g/kg soybean oil (p = 0.03) and 5.0 g/h/day probiotics significantly improved the nutritive value index of goat muscle. Collectively, the findings suggest that the optimal supplementation levels of probiotics and soybean oil are 2.5 g/h/day and 50 g/kg, respectively. These levels have a more pronounced effect on improving the growth performance of growing goats, increasing CLA content, and enhancing meat quality.

Conjugated Linoleic Acid Production in Pine Nut Oil: A Lactiplantibacillus plantarum Lp-01 Fermentation Approach

Conjugated linoleic acid (CLA) is a class of bioactive fatty acids that exhibit various physiological activities such as anti-cancer, anti-atherosclerosis, and lipid-lowering. It is an essential fatty acid that cannot be synthesized by the human body and must be derived from dietary sources. The natural sources of CLA are limited, predominantly relying on chemical and enzymatic syntheses methods. Microbial biosynthesis represents an environmentally benign approach for CLA production. Pine nut oil, containing 40-60% linoleic acid, serves as a promising substrate for CLA enrichment. In the present study, we developed a novel method for the production of CLA from pine nut oil using Lactiplantibacillus plantarum (L. plantarum) Lp-01, which harbors a linoleic acid isomerase. The optimal fermentation parameters for CLA production were determined using a combination of single-factor and response surface methodologies: an inoculum size of 2%, a fermentation temperature of 36 °C, a fermentation time of 20 h, and a pine nut oil concentration of 11%. Under these optimized conditions, the resultant CLA yield was 33.47 μg/mL. Gas chromatography analysis revealed that the fermentation process yielded a mixture of c9, t11CLA and t10, c12 CLA isomers, representing 4.91% and 4.86% of the total fatty acid content, respectively.

Factors influencing conjugated linoleic acid content of dairy products: challenges and strategies

Conjugated linoleic acid (CLA), a bioactive fatty acid that provides various physiological benefits, has gained increasing attention in the food industry, and various studies have focused on enhancing its content in dairy products. The factors influencing CLA content in dairy products vary significantly, including lactation stage, breed type, seasonality, feed, management methods of the animals, the manufacturing processes, storage, and ripening periods of the product. Additionally, the incorporation of CLA-producing probiotic bacteria, such as Lactobacillus, Lactococcus, Bifidobacterium, and Propionibacterium, is an emerging study in this field. Studies have revealed that factors affecting the CLA content in milk affect that in dairy products as well. Furthermore, the species and strains of CLA-producing bacteria, fermentation conditions, ripening period, and type of dairy product are also contributing factors. However, production of CLA-enhanced dairy products using CLA-producing bacteria while maintaining their optimal viability and maximizing exposure to free linoleic acid remains limited. The current review emphasized the factors affecting the CLA content and related mechanisms, challenges in the application of CLA-producing probiotic bacteria, and strategies to address these challenges and enhance CLA production in dairy products. Therefore, the development of functional dairy products with enhanced CLA levels is expected to be possible.

Production of Conjugated Linoleic Acid (CLA) by Lactiplantibacillus plantarum: A Review with Emphasis on Fermented Foods

The term Conjugated Linoleic Acid (CLA) refers generically to a class of positional and geometric conjugated dienoic isomers of linoleic acid. Among the isomers of linoleic acid cis9, trans11-CLA (c9, t11-CLA) and trans10, cis12-CLA (t10, c12-CLA) are found to be biologically active isomers, and they occur naturally in milk, dairy products and meat from ruminants. In addition, some vegetables and some seafoods have also been reported to contain CLA. Although the CLA levels in these natural sources are insufficient to confer the essential health benefits, anti-carcinogenic or anti-cancer effects are of current interest. In the rumen, CLA is an intermediate of isomerization and the biohydrogenation process of linoleic acid to stearic acid conducted by ruminal microorganisms. In addition to rumen bacteria, some other bacteria, such as Propionibacterium, Bifidobacterium and some lactic acid bacteria (LAB) are also capable of producing CLA. In this regard, Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) has demonstrated the ability to produce CLA isomers from linoleic acid by multiple enzymatic activities, including hydration, dehydration, and isomerization. L. plantarum is one of the most versatile species of LAB and the bacterium is widely used in the food industry as a microbial food culture. Thus, in this review we critically analyzed the literature produced in the last ten years with the aim to highlight the potentiality as well as the optimal conditions for CLA production by L. plantarum. Evidence was provided suggesting that the use of appropriate strains of L. plantarum, as a starter or additional culture in the production of some fermented foods, can be considered a critical factor in the design of new CLA-enriched functional foods.

Conjugated linoleic acid (CLA) as a functional food: Is it beneficial or not?

Conjugated linoleic acid (CLA) has attracted great attention in recent years as a popular class of functional food that is broadly used. It refers to a group of geometric and positional isomers of linoleic acid (LA) with a conjugated double bond. The main natural sources of CLA are dairy products, beef and lamb, whereas only trace amounts occur naturally in plant lipids. CLA has been shown to improve various health issues, having effects on obesity, inflammatory, anti-carcinogenicity, atherogenicity, immunomodulation, and osteosynthesis. Also, compared to studies on humans, many animal researches reveal more positive benefits on health. CLA represents a nutritional avenue to improve lifestyle diseases and metabolic syndrome. Most of these effects are attributed to the two major CLA isomers [conjugated linoleic acid cis-9,trans-11 isomer (c9,t11), and conjugated linoleic acid trans-10,cis-12 isomer (t10,c12)], and their mixture (CLA mix). In contrast, adverse effects of CLA have been also reported, such as glucose homeostasis, insulin resistance, hepatic steatosis and induction of colon carcinogenesis in humans, as well as milk fat inhibition in ruminants, lowering chicken productivity, influencing egg quality and altering growth performance in fish. This review article aims to discuss the health benefits of CLA as a nutraceutical supplement and highlight the possible mechanisms of action that may contribute to its outcome. It also outlines the feasible adverse effects of CLA besides summarizing the recent peer-reviewed publications on CLA to ensure its efficacy and safety for proper application in humans.

Production and Optimization of Conjugated Linoleic and Eicosapentaenoic Acids by Bifidobacterium lactis in Cold-Pressed Soybean Cake

Background and Purpose

In regard to the biosynthesis of conjugated linoleic acid (CLA) and eicosapentaenoic acid (EPA) by some bacteria, the objective of this study was to evaluate the efficiency of solid-state fermentation based on soybean pressed cake (SPC) to produce CLA and EPA by Bifidobacterium lactis. The objective of this study was to evaluate the efficiency of solid-state fermentation based on SPC to produce CLA and EPA by B. lactis.

Methods

Process conditions including humidity, inoculation level, and temperature parameters were optimized by adopting the response surface methodology (RSM) method (response surface method) and the design expert software. Accordingly, a homogeneous SPC paste substrate at 60, 70, and 80% humidity was prepared with different inoculation levels at 30, 37, and 44°C to assess the strain behavior. The introduced SPC consisted of 60% humidity, 2% inoculation level at 37°C, and 60% humidity, and 4% inoculation level at 30 and 44°C; it also included 6% inoculation level at 37°C, 70% humidity at 2% inoculation level, at 30 and 44°C, and 4% inoculation level at 37°C. Also, SPC with 80% humidity at 2% and 4% inoculation levels, and at 30 and 44°C was obtained. To confirm the accuracy of the conditions, an experiment was conducted according to the defined requirements.

Results

The results were compared with the predicted data, which showed a significant difference. Under optimized conditions, with an inoculation level of 4% on the SPC medium with 70% humidity and at 37°C, B. lactis strains could yield 9cis-, 11 trans-linoleic and eicosapentaenoic at 0.18 and 0.39% of the total fatty acids.

Conclusion

So, the potential benefits of using SPC as an inexpensive substrate for the commercial production of CLA and EPA should be noted.

Lactic Acid Bacteria in Raw-Milk Cheeses: From Starter Cultures to Probiotic Functions

Traditional cheeses produced from raw milk exhibit a complex microbiota, characterized by a sequence of different microorganisms from milk coagulation and throughout maturation. Lactic acid bacteria (LAB) play an essential role in traditional cheese making, either as starter cultures that cause the rapid acidification of milk or as secondary microbiota that play an important role during cheese ripening. The enzymes produced by such dynamic LAB communities in raw milk are crucial, since they support proteolysis and lipolysis as chief drivers of flavor and texture of cheese. Recently, several LAB species have been characterized and used as probiotics that successfully promote human health. This review highlights the latest trends encompassing LAB acting in traditional raw milk cheeses (from cow, sheep, and goat milk), and their potential as probiotics and producers of bioactive compounds with health-promoting effects.

Tackling Atherosclerosis via Selected Nutrition

The development and pathogenesis of atherosclerosis are significantly influenced by lifestyle, particularly nutrition. The modern level of science and technology development promote personalized nutrition as an efficient preventive measure against atherosclerosis. In this survey, the factors were revealed that contribute to the formation of an individual approach to nutrition: genetic characteristics, the state of the microbiota of the gastrointestinal tract (GIT) and environmental factors (diets, bioactive components, cardioprotectors, etc.). In the course of the work, it was found that in order to analyze the predisposition to atherosclerosis associated with nutrition, genetic features affecting the metabolism of nutrients are significant. The genetic features include the presence of single nucleotide polymorphisms (SNP) of genes and epigenetic factors. The influence of telomere length on the pathogenesis of atherosclerosis and circadian rhythms was also considered. Relatively new is the study of the relationship between chrono-nutrition and the development of metabolic diseases. That is, to obtain the relationship between nutrition and atherosclerosis, a large number of genetic markers should be considered. In this relation, the question arises: "How many genetic features need to be analyzed in order to form a personalized diet for the consumer?" Basically, companies engaged in nutrigenetic research and choosing a diet for the prevention of a number of metabolic diseases use SNP analysis of genes that accounts for lipid metabolism, vitamins, the body's antioxidant defense system, taste characteristics, etc. There is no set number of genetic markers. The main diets effective against the development of atherosclerosis were considered, and the most popular were the ketogenic, Mediterranean, and DASH-diets. The advantage of these diets is the content of foods with a low amount of carbohydrates, a high amount of vegetables, fruits and berries, as well as foods rich in antioxidants. However, due to the restrictions associated with climatic, geographical, material features, these diets are not available for a number of consumers. The way out is the use of functional products, dietary supplements. In this approach, the promising biologically active substances (BAS) that exhibit anti-atherosclerotic potential are: baicalin, resveratrol, curcumin, quercetin and other plant metabolites. Among the substances, those of animal origin are popular: squalene, coenzyme Q10, omega-3. For the prevention of atherosclerosis through personalized nutrition, it is necessary to analyze the genetic characteristics (SNP) associated with the metabolism of nutrients, to assess the state of the microbiota of the GIT. Based on the data obtained and food preferences, as well as the individual capabilities of the consumer, the optimal diet can be selected. It is topical to exclude nutrients of which their excess consumption stimulates the occurrence and pathogenesis of atherosclerosis and to enrich the diet with functional foods (FF), BAS containing the necessary anti-atherosclerotic, and stimulating microbiota of the GIT nutrients. Personalized nutrition is a topical preventive measure and there are a number of problems hindering the active use of this approach among consumers. The key factors include weak evidence of the influence of a number of genetic features, the high cost of the approach, and difficulties in the interpretation of the results. Eliminating these deficiencies will contribute to the maintenance of a healthy state of the population through nutrition.

Underlying evidence for the health benefits of fermented foods in humans

Fermented foods (FFs) have been a part of our diets for millennia and comprise highly diverse products obtained from plants and animals all over the world. Historically, fermentation has been used to preserve food and render certain raw materials edible. As our food systems evolve towards more sustainability, the health benefits of FFs have been increasingly touted. Fermentation generates new/transformed bioactive compounds that may occur in association with probiotic bacteria. The result can be specific, advantageous functional properties. Yet, when considering the body of human studies on the topic, whether observational or experimental, it is rare to come across findings supporting the above assertion. Certainly, results are lacking to confirm the widespread idea that FFs have general health benefits. There are some exceptions, such as in the case of lactose degradation via fermentation in individuals who are lactose intolerant; the impact of select fermented dairy products on insulin sensitivity; or the benefits of alcohol consumption. However, in other situations, the results fail to categorically indicate whether FFs have neutral, beneficial, or detrimental effects on human health. This review tackles this apparent incongruity by showing why it is complex to test the health effects of FFs and what can be done to improve knowledge in this field.

Effects of Icariin on Modulating Gut Microbiota and Regulating Metabolite Alterations to Prevent Bone Loss in Ovariectomized Rat Model

Postmenopausal osteoporosis (PMOP) is an estrogen deficiency-induced bone loss, which has been shown an association with an altered gut microbiota (GM). Gut microbiota-bone axis has been recognized as a crucial mediator for bone homeostasis. Icariin (ICA) is an effective agent to delay bone loss by regulating the bone homeostasis. Thus, we hypothesize that ICA can prevent bone loss by modulating GM and regulating metabolite alterations. The effects of ICA on bone metabolism improvement in ovariectomized (OVX) rats and their relationships with the GM and fecal metabolites were investigated. Micro-computed tomography (micro-CT) and hematoxylin-eosin (HE) staining showed a typical bone boss in OVX group, while ICA or estradiol (E2) administration exhibited positive effects on bone micro-architecture improvement. The GM such as Actinobacteria, Gammaproteobacteria, Erysipelotrichi, Erysipelotrichales, Enterobacteriales, Actinomycetales, Ruminococcus and Oscillospira significantly correlated to serum bone Gla-protein (BGP), receptor activator of nuclear factor-κB (RANK), receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG) and tartrate resistant acid phosphatase (TRACP). Further t-test revealed a substantial variation of the GM and fecal metabolites in different treatments. Among them, Lachnoclostridium, Butyricimonas, Rikenella, Paraprevolla, Adlercreutzia, Enterorhabdus, Anaerovorax, Allobaculum, Elusimicrobium, Lactococcus, Globicatella and Lactobacillus were probably the key microbial communities driving the change of bile acid, amino acid and fatty acid, thereby leading to an improvement of PMOP. The significant up-regulation of L-Saccharopine, 1-Aminocyclohexadieneacid and linoleic acid after ICA administration suggested important contributions of amino acid and fatty acid metabolisms in the prevention and treatment of PMOP. Taken together, our study has provided new perspectives to better understand the effects of ICA on PMOP improvement by regulating GM and the associated fecal metabolites. Our findings contribute to develop ICA as a potential therapy for PMOP.

Oleate Hydratase in Lactobacillus delbrueckii subsp. bulgaricus LBP UFSC 2230 Catalyzes the Reversible Conversion between Linoleic Acid and Ricinoleic Acid

Conjugated linoleic acid (CLA) has been the subject of numerous studies in recent decades because of its associated health benefits. CLA is an intermediate product of the biohydrogenation pathway of linoleic acid (LA) in bacteria. Several bacterial species capable of efficiently converting LA into CLA have been widely reported in the literature, among them Lactobacillus delbrueckii subsp. bulgaricus LBP UFSC 2230. Over the last few years, a multicomponent enzymatic system consisting of three enzymes involved in the biohydrogenation process of LA has been proposed. Sequencing the genome of L. delbrueckii subsp. bulgaricus LBP UFSC 2230 revealed only one gene capable of encoding an oleate hydratase (OleH), unlike the presence of multiple genes typically found in similar strains. This study investigated the biological effect of the OleH enzyme of L. delbrueckii subsp. bulgaricus LBP UFSC 2230 on the hydration of LA and dehydration of ricinoleic acid (RA) and its possible role in the production of CLA. The OleH was cloned, expressed, purified, and characterized. Fatty acid measurements were made by an internal standard method using a gas chromatography-coupled flame ionization detector (GC-FID) system. It was found that the enzyme is a hydratase/dehydratase, leading to a reversible transformation between LA and RA. In addition, the results showed that L. delbrueckii subsp. bulgaricus LBP UFSC 2230 OleH protein plays a role in stress tolerance in Escherichia coli. In conclusion, the OleH of L. delbrueckii subsp. bulgaricus LBP UFSC 2230 catalyzes the initial stage of saturation metabolism of LA, although it has not converted the substrates directly into CLA. IMPORTANCE This study provides insight into the enzymatic mechanism of CLA synthesis in L. delbrueckii subsp. bulgaricus and broadens our understanding of the bioconversion of LA and RA by OleH. The impact of OleH on the production of the c9, t11 CLA isomer and stress tolerance by E. coli has been assisted. The results provide an understanding of the factors which influence OleH activity. L. delbrueckii subsp. bulgaricus LBP UFSC 2230 OleH presented two putative fatty acid-binding sites. Recombinant OleH catalyzed both LA hydration and RA dehydration. OleH was shown to play a role in bacterial growth performance in the presence of LA.

Bovine Colostrum for Human Consumption—Improving Microbial Quality and Maintaining Bioactive Characteristics through Processing

The main purpose of bovine colostrum, being the milk secreted by a cow after giving birth, is to transfer passive immunity to the calf. The calves have an immature immune system as they lack immunoglobulins (Igs). Subsequently, the supply of good quality bovine colostrum is required. The quality of colostrum is classified by low bacterial counts and adequate Ig concentrations. Bacterial contamination can contain a variety of human pathogens or high counts of spoilage bacteria, which has become more challenging with the emerging use of bovine colostrum as food and food supplements. There is also a growing risk for the spread of zoonotic diseases originating from bovines. For this reason, processing based on heat treatment or other feasible techniques is required. This review provides an overview of literature on the microbial quality of bovine colostrum and processing methods to improve its microbial quality and keep its nutritional values as food. The highlights of this review are as follows: high quality colostrum is a valuable raw material in food products and supplements; the microbial safety of bovine colostrum is increased using an appropriate processing-suitable effective heat treatment which does not destroy the high nutrition value of colostrum; the heat treatment processes are cost-effective compared to other methods; and heat treatment can be performed in both small- and large-scale production.