Seminal bacterial composition in patients with obstructive and non-obstructive azoospermia

Changes in the microbial community of semen exposed to different simulated forensic situations

Semen is one of the common body fluids in sexual crime cases. The current methods of semen identification have certain limitations, so it is necessary to search for other methods. In addition, there are few reports of microbiome changes in body fluids under simulated crime scenes. It is essential to further reveal the changes in semen microbiomes after exposure to various simulated crime scenes. Semen samples from eight volunteers were exposed in closed plastic bags, soil, indoor, cotton, polyester, and wool fabrics. A total of 68 samples (before and after exposure) were collected, detected by 16S rDNA sequencing, and analyzed for the microbiome signature. Finally, a random forest model was constructed for body fluid identification. After exposure, the relative abundance of Pseudomonas and Rhodococcus changed dramatically in almost all groups. In addition, the treatment with the closed plastic bags or soil groups had a greater impact on the semen microbiome. According to the Shannon indices, the alpha diversity of the closed plastic bags and soil groups was much lower than that of the other groups. Attention should be given to the above two scenes in practical work of forensic medicine. In this study, the accuracy of semen recognition was 100%. The exposed semen can still be correctly identified as semen based on its microbiota characteristics. In summary, semen microbiomes exposed to simulated crime scenes still have good application potential for body fluid identification.

IMPORTANCE

In this study, the microbiome changes of semen exposed to different environments were observed, and the exposed semen microbiome still has a good application potential in body fluid identification.

The elusive male microbiome: revealing the link between the genital microbiota and fertility. Critical review and future perspectives

There is a growing focus on understanding the role of the male microbiome in fertility issues. Although research on the bacterial communities within the male reproductive system is in its initial phases, recent discoveries highlight notable variations in the microbiome's composition and abundance across distinct anatomical regions like the skin, foreskin, urethra, and coronary sulcus. To assess the relationship between male genitourinary microbiome and reproduction, we queried various databases, including MEDLINE (available via PubMed), SCOPUS, and Web of Science to obtain evidence-based data. The literature search was conducted using the following terms "gut/intestines microbiome," "genitourinary system microbiome," "microbiome and female/male infertility," "external genital tract microbiome," "internal genital tract microbiome," and "semen microbiome." Fifty-one relevant papers were analyzed, and eleven were strictly semen quality or male fertility related. The male microbiome, especially in the accessory glands like the prostate, seminal vesicles, and bulbourethral glands, has garnered significant interest because of its potential link to male fertility and reproduction. Studies have also found differences in bacterial diversity present in the testicular tissue of normozoospermic men compared to azoospermic suggesting a possible role of bacterial dysbiosis and reproduction. Correlation between the bacterial taxa in the genital microbiota of sexual partners has also been found, and sexual activity can influence the composition of the urogenital microbiota. Exploring the microbial world within the male reproductive system and its influence on fertility opens doors to developing ways to prevent, diagnose, and treat infertility. The present work emphasizes the importance of using consistent methods, conducting long-term studies, and deepening our understanding of how the reproductive tract microbiome works. This helps make research comparable, pinpoint potential interventions, and smoothly apply microbiome insights to real-world clinical practices.

Effect of environmental factors on seminal microbiome and impact on sperm quality

Objective

This review provides a comprehensive overview of the existing research on the seminal microbiome and its association with male infertility, while also highlighting areas that warrant further investigation.

Methods

A narrative review was conducted, encompassing all relevant studies published between 1980-2023 on the male reproductive tract microbiome in humans. This review considered studies utilizing culture-based, polymerase chain reaction (PCR)-based, and next-generation sequencing (NGS)-based methodologies to analyze the microbiome. Data extraction encompassed sample types (semen or testicular tissue), study designs, participant characteristics, employed techniques, and critical findings.

Results

We included 37 studies comprising 9,310 participants. Among these, 16 studies used culture-based methods, 16 utilized NGS, and five employed a combination of methods for microorganism identification. Notably, none of the studies assessed fungi or viruses. All NGS-based studies identified the presence of bacteria in all semen samples. Two notable characteristics of the seminal microbiome were observed: substantial variability in species composition among individuals and the formation of microbial communities with a dominant species. Studies examining the testicular microbiome revealed that the testicular compartment is not sterile. Interestingly, sexually active couples shared 56% of predominant genera, and among couples with positive cultures in both partners, 61% of them shared at least one genital pathogen. In couples with infertility of known causes, there was an overlap in bacterial composition between the seminal and vaginal microbiomes, featuring an increased prevalence of Staphylococcus and Streptococcus genera. Furthermore, the seminal microbiome had discernible effects on reproductive outcomes. However, bacteria in IVF culture media did not seem to impact pregnancy rates.

Conclusion

Existing literature underscores that various genera of bacteria colonize the male reproductive tract. These organisms do not exist independently; instead, they play a pivotal role in regulating functions and maintaining hemostasis. Future research should prioritize longitudinal and prospective studies and investigations into the influence of infertility causes and commonly prescribed medication to enhance our understanding of the seminal microbiota's role in reproductive health.

Characterization of the semen, gut, and urine microbiota in patients with different semen abnormalities

Introduction

Semen quality is decreasing worldwide, leading to increased male infertility. This study analyzed the microbiota of the gut, semen, and urine in individuals with semen abnormalities to identify potential probiotics and pathogenic bacteria that affect semen parameters and help develop new methods for the diagnosis and treatment of patients with semen abnormalities.

Methods

We recruited 12 individuals with normal semen parameters (control group), 12 with asthenospermia but no semen hyperviscosity (Group_1), 6 with oligospermia (Group_2), 9 with severe oligospermia or azoospermia (Group_3), and 14 with semen hyperviscosity only (Group_4). The semen, gut, and urine microbiota were examined by analyzing the 16S ribosomal RNA gene sequence using next-generation sequencing.

Results

The gut microbes were clustered into the highest number of operational taxonomic units, followed by urine and semen. Furthermore, the α-diversity of gut microbes was highest and significantly different from that of urine and semen microbiota. The microbiota of the gut, urine, and semen were all significantly different from each other in terms of β-diversity. The gut abundance of Collinsella was significantly reduced in groups 1, 3, and 4. Furthermore, the gut abundance of Bifidobacterium and Blautia was significantly decreased in Group_1, while that of Bacteroides was significantly increased in Group_3. The abundance of Staphylococcus was significantly increased in the semen of groups 1 and 4. Finally, Lactobacillus abundance was significantly reduced in the urine of groups 2 and 4.

Discussion

This study comprehensively describes the differences in intestinal and genitourinary tract microbiota between healthy individuals and those with abnormal semen parameters. Furthermore, our study identified Collinsella, Bifidobacterium, Blautia, and Lactobacillus as potential probiotics. Finally, the study identified Bacteroides in the gut and Staphylococcus in semen as potential pathogenic bacteria. Our study lays the foundation of a new approach to the diagnosis and treatment of male infertility.

Seminal and vagino-uterine microbiome and their individual and interactive effects on cattle fertility

Reproductive failure is a major economical drain on cow-calf operations across the globe. It can occur in both males and females and stem from prenatal and postnatal influences. Therefore, the cattle industry has been making efforts to improve fertility and the pregnancy rate in cattle herds as an attempt to maintain sustainability and profitability of cattle production. Despite the advancements made in genetic selection, nutrition, and the implementation of various reproductive technologies, fertility rates have not significantly improved in the past 50 years. This signifies a missing factor or factors in current reproductive management practices that influence successful fertilization and pregnancy. Emerging lines of evidence derived from human and other animals including cattle suggest that the microbial continuum along the male and female reproductive tracts are associated with male and female fertility-that is, fertilization, implantation, and pregnancy success-highlighting the potential for harnessing the male and female reproductive microbiome to improve fertility in cattle. The objective of this narrative review is to provide an overview of the recent studies on the bovine seminal and vagino-uterine microbiome and discuss individual and interactive roles of these microbial communities in defining cattle fertility.

Semen dysbiosis—just a male problem?

Seminal microflora is crucial to male fertility. Dysbiosis—disturbance of quantitative ratios of individual bacteria or appearance of pathogenic species—rarely results in symptomatic disease. Inflammation results in decreased sperm production, lower motility, or morphological changes and, in the long term, can cause ejaculatory duct obstruction, leading to infertility. Moreover, it may cause infection of the partner’s female genital tract. Dysbiosis in both partners results in fertility problems, disorders in embryo implantation, or miscarriages. In addition, chronic inflammation of the male genitourinary system may accelerate the appearance of antisperm antibodies. A comprehensive examination of seminal microflora can clarify the causes of infertility or prevent pathological conditions that affect seminal parameters. Seminal microflora as a direct impact on fertility problems as well as a decrease in the effectiveness of assisted reproduction methods, insemination, or in vitro procedures.

Seminal Microbiota of Idiopathic Infertile Patients and Its Relationship With Sperm DNA Integrity

The development of new biomarkers for human male infertility is crucial to improve the diagnosis and the prognosis of this disease. Recently, seminal microbiota was shown to be related to sperm quality parameters, suggesting an effect in human fertility and postulating it as a biomarker candidate. However, its relationship to sperm DNA integrity has not been studied yet. The aim of the present study is to characterize the seminal microbiota of a western Mediterranean population and to evaluate its relationship to sperm chromatin integrity parameters, and oxidative stress. For that purpose, 14 samples from sperm donors and 42 samples from infertile idiopathic patients were obtained and were analyzed to assess the composition of the microbiota through full-length 16S rRNA gene sequencing (Illumina MiSeq platform). Microbial diversity and relative abundances were compared to classic sperm quality parameters (macroscopic semen parameters, motility, morphology and concentration), chromatin integrity (global DNA damage, double-stranded DNA breaks and DNA protamination status) and oxidative stress levels (oxidation-reduction potential). The seminal microbiota observed of these samples belonged to the phyla Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. The most abundant genera were Finegoldia, Peptoniphilus, Anaerococcus, Campylobacter, Streptococcus, Staphylococcus, Moraxella, Prevotella, Ezakiella, Corynebacterium and Lactobacillus. To our knowledge, this is the first detection of Ezakiella genus in seminal samples. Two clusters of microbial profiles were built based on a clustering analysis, and specific genera were found with different frequencies in relation to seminal quality defects. The abundances of several bacteria negatively correlate with the sperm global DNA fragmentation, most notably Moraxella, Brevundimonas and Flavobacterium. The latter two were also associated with higher sperm motility and Brevundimonas additionally with lower oxidative-reduction potential. Actinomycetaceae, Ralstonia and Paenibacillus correlated with reduced chromatin protamination status and increased double-stranded DNA fragmentation. These effects on DNA integrity coincide in many cases with the metabolism or enzymatic activities of these genera. Significant differences between fertile and infertile men were found in the relative presence of the Propionibacteriaceae family and the Cutibacterium, Rhodopseudomonas and Oligotropha genera, which supports its possible involvement in male fertility. Our findings sustain the hypothesis that the seminal microbiome has an effect on male fertility.

Seminal and testicular microbiome and male fertility: A systematic review

Supplemental Digital Content is available in the text

Microbiome is of upmost importance for the well-being of the human body. Based on culture and PCR methods, seminal flora has been pointed as a potential cause for some of the unexplained male infertility.

This is a systematic review about the effect of seminal microbiota studied by Next Generation Sequencing techniques on sperm quality and male fertility, performed according to PRISMA statement.

Nine articles were included. Results of different studies are diverse. It seems that microbiota may a play a role in seminal quality and further male fertility, but the way this effect is modulated is still to be unknown. Lactobacillus spp seemed to play a beneficial role in semen quality, but the role of the remaining bacteria is unclear.

Due to the lack of research and the incongruence of the results so far, the effect of microbiota on seminal quality is still unclear.

Сondition of urogenital tract microbiotes and pro- and antioxidant system in male azoospermia

Over the past 20 years, there has been a clear trend to increase in the number of infertile men in Ukraine, their percentage reaches 50% in infertile couples. There is a significant percentage of male infertility caused by azoospermia – the lack of sperm in the ejaculate. In male infertility, azoospermia is found in 10–15% of patients, among other forms of pathospermia. Given the ambiguity of ideas about the etiology, pathogenesis and treatment and diagnostic approaches for various types of infertility, it remains important to clarify the relationship of urogenital infections with the regulatory systems of cells, including the state of the pro- and antioxidant system and the search for additional markers. 119 patients with various forms of azoospermia were examined. All patients underwent the following studies: spermogram, infectious screening, inhibin B, lipid peroxidation, activity of enzymes of the glutathione antioxidant system in sperm plasma and blood serum. Infectious screening included analysis of urethral secretions, bacteriological examination of sperm or prostate secretion, assessment of the species and quantitative composition of the microflora of the male urogenital tract. According to the results of spermogram and other diagnostic methods, a non-obstructive form of azoospermia was detected in 69 patients. In obstructive azoospermia, ejaculate as such was absent. It is suggested that inhibin B may be an important medical diagnostic test for azoospermia. As a result of the conducted researches the importance of determining the concentration of inhibin B as a marker of azoospermia was demonstrated and a negative correlation of moderate strength between the content of inhibin B and testosterone level in the plasma of men with non-obstructive azoospermia was revealed. It was found that Ureaplasma pervum and Ureaplasma urealyticum infect the male genitourinary system to the greatest extent among a number of microorganisms, both in non-obstructive and obstructive forms of azoospermia. Enterococcus faecalis is more pronounced in the sperm fluid in the non-obstructive form of azoospermia and prostate secreton in the obstructive form of azoospermia. In the non-obstructive form of azoospermia in the seminal plasma and serum, the processes of lipid peroxidation intensify, the concentration of reduced glutathione decreases and the activities of the enzymes of the glutathione antioxidant system (glutathione peroxidase and glutathione transferase) decrease. It can be considered that an important diagnostic test for the nonobstructive form of azoospermia is the ratio of reduced glutathione to oxidized glutathione in sperm plasma.

Genomic Sequencing Reveals the Diversity of Seminal Bacteria and Relationships to Reproductive Potential in Boar Sperm

A number of emerging studies suggest that pathogenic microorganisms in semen may cause a decline in the reproductive potential of spermatozoa, and the bacterial diversity and profile of ejaculated boar semen in different seasons are currently unknown. To explore the bacterial composition and changes in ejaculated boar semen from winter and summer, and the underlying mechanism of decline in sperm quality and fertility capacity in summer, 120 ejaculated semen samples were examined for bacterial communities using genomic sequencing technology, and the associations between microbial composition and sperm reproductive potential were investigated. The results showed that Proteobacteria (57.53%), Firmicutes (31.17%), Bacteroidetes (4.24%), and Actinobacteria (3.41%) are the dominant phyla in the ejaculated semen, and the dominant genera were Pseudomonas (34.41%) and Lactobacillus (19.93%), which belong to the phyla of Proteobacteria and Firmicutes, respectively. Interestingly, the higher diversity of bacteria in ejaculated semen of winter differs from that of summer semen, potentially due to seasonal changes related to changes in semen quality and sperm fertilizing capacity. Furthermore, the highly abundant Lactobacillus in winter samples were positively associated with sperm quality and reproductive performance obtained from sows inseminated with such semen samples, while in contrast, the highly abundant Pseudomonas in summer samples was negatively associated with sperm quality and reproductive potential. Additionally, our results strongly indicated that Lactobacillus is not only a potential probiotic for semen quality and fertility potential but also beneficial for restraining the negative influence of Pseudomonas. Overall, our findings significantly contribute to the current understanding of the phenotypes and etiology of male "summer infertility," and may represent a frontier in male reproductive disorders and possible early prevention against pathogenic bacteria.

The Disordered Vaginal Microbiota Is a Potential Indicator for a Higher Failure of in vitro Fertilization

Infertility is one of the most common reproductive system diseases, and no effective method is available for its treatment. Although in vitro fertilization (IVF) has been widely used to enhance the clinical pregnancy outcome of infertility, the unsatisfied pregnancy rate with unknown reasons is obtained. To identify the possible cause of IVF failure, 555 patients were enrolled in the present study to determine their relevant clinical characteristics and vaginal microbiota. Our results indicated that the age and endometrium thickness significantly affected the pregnancy success rate of pregnant patients (P group) and non-pregnant patients (NP group) receiving IVF, and high values of luteinizing hormone, estrogen and progesterone were observed from P group. Furthermore, the Partial Least Squares Discriminant Analysis (PLS-DA) indicated a different microbial composition in P group and NP group, and a higher microbial abundance had been identified in non-pregnant patients compared with pregnant patients. At phylum level, a higher abundance of Firmicutes and Proteobacteria, and a lower abundance of Actinobacteria, Fusobacteria, and Bacteroidetes were obtained in pregnant patients compared with non-pregnant patients. At genus level, a lower abundance of the probiotic Lactobacillus, and higher abundance of pathogens Gardnerella and Prevotella were identified from non-pregnant patients. Therefore, the disordered microbiota, characterizing by the reduction of probiotics and overgrowth of pathogens in non-pregnant patients, may be used as a potential indicator for a higher IVF failure rate.

Microbiota and Human Reproduction: The Case of Male Infertility

The increasing interest in metagenomics is enhancing our knowledge regarding the composition and role of the microbiota in human physiology and pathology. Indeed, microbes have been reported to play a role in several diseases, including infertility. In particular, the male seminal microbiota has been suggested as an important factor able to influence couple’s health and pregnancy outcomes, as well as offspring health. Nevertheless, few studies have been carried out to date to deeper investigate semen microbiome origins and functions, and its correlations with the partner’s reproductive tract microbiome. Here, we report the state of the art regarding the male reproductive system microbiome and its alterations in infertility.

Evaluation of the inhibitory effects of vaginal microorganisms on sperm motility in vitro

Female infertility usually occurs as a result of ageing, physical impairment, hormone disturbances and lifestyle or environmental factors. However, the potential role of Lactobacillus in female infertility has remained largely unexplored. In the present study, high-throughput sequencing, real-time PCR, bacterial adherence assays and sperm motility assays were used to evaluate the microbial diversity, adherence properties and effect on sperm motility of sperm bacteria, vaginal bacteria and vaginal bacteria that had been co-cultured with sperm. The results indicated that in the co-culture group, Lactobacillus adhered to sperm cells in numbers that were 332-fold higher than those of control species Enterococcus and analysis of sequencing data using the Kyoto Encyclopedia of Genes and Genomes indicated that adhered microbes reduced sperm cell motility. Vaginal isolates, as well as bacterial strains used as controls, were co-cultured with sperm and it was indicated that all strains were able to adhere to sperm cells in large numbers. The probiotic Lactobacillus (L.) strains L. crispatus, L. acidophilus, L. helveticus and L. gasseri significantly reduced sperm motility (based on measurements of general, straightforward and non-straightforward progressive motility, total motility and average path velocity; P<0.05). Furthermore, L. crispatus, L. acidophilus, L. salivarius, L. helveticus and L. gasseri markedly reduced sperm penetration in a viscous medium. Based on these results, it may be hypothesized that the weakening effect of Lactobacillus on sperm motility may be beneficial for healthy couples to prevent the combination of abnormal sperms and eggs, but may be detrimental for males with severe asthenospermia, oligospermia or aspermia.

The impact of microbiome in urological diseases: a systematic review

OBJECTIVE

The term microbiome is used to signify the ecological community of commensal, symbiotic, and pathogenic microorganisms that share our body space, in which there were increasing evidences to suggest that they might have potential roles in various medical conditions. While the study of microbiome in the urinary system is not as robust as the systems included in the Human Microbiome Project, there are still evidences in the literature showing that microbiome may have a role in urological diseases. Therefore, we would like to perform a systematic review on the topic and summarize the available evidence on the impact of microbiome on urological diseases.

METHODOLOGY

This review was performed according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. After screening 589 abstracts and including additional studies (such as references from review papers), 76 studies were included for review and discussion.

RESULTS

Studies had suggested that there were correlations of microbiome of different body cavities (e.g., fecal, urinary and seminal fluid) with urological diseases. Also, different diseases would have different microbiome profile in different body cavities. Unfortunately, the studies on the association of microbiome and urological diseases were still either weak or inconsistent.

CONCLUSION

Studies suggested that there might be some relationship between microbiome and various urological diseases. However, further large-scale studies with control of confounding factors should be performed under a standardized methodology in order to have better understanding of the relationship. Also, more standardized reporting protocol for microbiome studies should be considered for better communications in future studies.

Revealing the interaction between intrauterine adhesion and vaginal microbiota using high‑throughput sequencing

Intrauterine adhesion (IUA) is one of the most common diseases of the reproductive system. Due to the high postoperative recurrence rate of IUA, it is crucial to identify the possible causes of pathogenesis and recurrence of this disease. In the present study, a high‑throughput sequencing approach was applied to compare the vaginal microbiota between healthy women [healthy vaginal secretion (HVS) group] and patients with IUA [intrauterine adhesion patients' vaginal secretion (IAVS) group]. The results indicated that IUA had little effect on the number of vaginal bacterial species. However, at the phylum level, patients with IUA had a significantly lower percentage of Firmicutes and a higher percentage of Actinobacteria than the HVS group (P<0.05). At the genus level, ~50% of patients with IUA were found to have a marked reduction in probiotic Lactobacillus accompanied by an overgrowth of pathogenic Gardnerella and Prevotella (P<0.05), and the Principal Coordinates Analysis confirmed that 10/20 samples in the IAVS group were scattered far away from the HVS group. Therefore, it was concluded that the interaction between IUA and vaginal microbiota greatly influenced the vaginal diversity of patients with IUA. In order to increase the recovery rate and lower the recurrence rate of IUA, increasing the vaginal Lactobacillus population should be considered.

A randomised trial of probiotics to reduce severity of physiological and microbial disorders induced by partial gastrectomy for patients with gastric cancer

Gastrectomy has been widely used for the treatment of gastric cancer, and the severity of physiological and microbial disorders has greatly harmed the health of patients. In the present study, a probiotic combination containing Bifidobacterium infantis, Lactobacillus acidophilus, Enterococcus faecalis and Bacillus cereus was used to reduce the physiological disorders induced by gastrectomy via monitoring the blood index and microbial diversity using high-throughput sequencing. Our results indicated that the probiotic combination had significantly reduced the inflammation indexes (leukocyte) (p<0.05), while it markedly enhanced the immunity indexes (lymphocyte) and nutrition indexes (albumin and total protein) (p<0.05). In addition, gastric cancer had a strong influence on the microbial diversity of the stomach via enhancing the number of pathogens of Streptococcus, Peptostreptococcus and Prevotella, and reducing the percentage of the probiotic Bifidobacterium. Although partial gastrectomy markedly changed intestinal microbial diversity, the taking of the probiotic combination greatly reduced the ratio of Firmicutes/Bacteroidetes compared with patients taking no probiotics at the phylum level. At the genus level, the probiotic combination significantly enhanced the numbers of the probiotic bacteria Bacteroides, Faecalibacterium and Akkermansia and lowered the richness of Streptococcus. Therefore, we concluded that the taking of the probiotic combination significantly enhances the immune response of patients and reduces the severity of inflammation through modification of gut microbiota.

Shaping Microbiota During the First 1000 Days of Life

The data obtained in prior studies suggest that early microbial exposition begins prior to conception and gestation. Given that the host-microbe interaction is shaped by the immune system response, it is important to understand the key immune system-microbiota relationship during the period from conception to the first years of life. The present work summarizes the available evidence concerning early microbiota exposure within the male and the female reproductive tracts at the point of conception and during gestation, focusing on the potential impact on infant development during the first 1000 days of life. Furthermore, we conclude that some dietary strategies including specific probiotics could become potentially valuable tools to modulate the gut microbiota during this early critical window of opportunity for targeted health outcomes throughout the entire lifespan.

Evaluation of the potential of chicoric acid as a natural food antioxidant

Dietary fat is important for human health, while its excessive consumption or the oxidation of lipids may cause various diseases. In the present study, the potential of chicoric acid (CA) as a natural food antioxidant was evaluated. To evaluate this, spectrophotometry analysis measured CA antioxidant activity, the analytical method of the sanitary standard of edible lard and rapeseed oil measured CA anti-oil oxidation, the Oxford cup method measured CA anti-microbial activity, Oil red O staining assessed intracellular triglycerides following CA administration, and RT-qPCR analysis and ELISA assessed CA anti-inflammatory activity. The results indicated that CA had a marked scavenging capacity for the 2,2-diphenyl-1-picrylhydrazyl radical, as well as a reductive action, and after incubation for 5 days, 0.05% CA achieved a significantly higher peroxide value than 0.02% tert-butylhydroquinone used as a reference (P<0.05). In addition, 160 nM CA inhibited the growth of a variety of common pathogenic microbes in humans, significantly inhibited fat droplet formation (P<0.05) and reduced the production of interleukin-1β and tumor necrosis factor-α in a dose-dependent manner (P<0.05). Therefore, functional foods containing CA may be used as natural antioxidant supplements to prevent the oxidation of oil and protect human health.