Probiotics have been proposed as alternatives to pharmacological products in several medical conditions including the modulation of obesity, which is frequently associated with poor semen quality. However, effects of probiotics on male fertility have been less investigated. This study assessed the effect of Lactobacillus rhamnosus PB01 (DSM-14870) on sperm kinematic parameters in Normal-weight (NW) and diet-induced obese (DIO) models. NW and DIO C57BL/6NTac mice were divided into two subgroups with or without a single daily dose (1x10⁹CFU) of L. rhamnosus for four weeks. Sperm motility and kinematics together with blood lipid profiles and reproductive hormone levels were assessed using the sperm class analyzer system. Probiotic supplementation increased serum testosterone, LH and FSH levels in both NW and DIO groups resulting in significantly (P<0.05) higher velocity (VSL, VCL and VAP) and percentages of progressively motile sperm and significantly lower percentages of immotile sperm. Other kinematic parameters (Lin, STR, ALH and BCF) were also increased in both probiotic supplemented DIO and NW groups at the 10% level of significance. Probiotic supplemented DIO mice demonstrated significantly higher percentages of progressively motile sperm versus DIO controls. This study demonstrated the potential of L. rhamnosus PB01 as a regulatory agent with positive effects on weight loss and reproductive-hormones, significantly improving sperm motility and kinematic parameters in male DIO models.

The effect of Glycyrrhiza glabra extract (GgE) as a natural antioxidant and melatonin (MEL) on ochratoxin A (OTA)-induced histopathological damages on the testes and oxidative stress was evaluated in male rats. The animals were assigned into four groups (n = 8) including control and test groups. The rats in control group received saline and the animals in the test groups received (200 µg/kg) of OTA, (15 mg/kg) of MEL + (200 µg/kg) OTA and (100 mg/kg) of GgE + (200 µg/kg) OTA, respectively, during 28 consecutive days. The serum total antioxidant power (TAOP) and total thiol molecules (TTM) production were assessed. Moreover, histopathological and histochemical studies were also performed. The results showed that the TAOP and TTM were decreased in OTA-exposed rats, while the animals that received MEL + OTA or GgE + OTA showed an enhancement in the serum TAOP and TTM levels. Histopathological analyses demonstrated that in OTA-exposed rats, the testicular degeneration, seminiferous tubule atrophy, dissociation of germinative epithelium, vasodilatation with vascular thrombosis, perivascular immune cell infiltration, hypertrophied leydic cells, giant cell formation, and negative tubular differentiation index (TDI) were observed. Surprisingly, both the biochemical and histopathological examinations showed that MEL and GgE, albeit with some differences, exerted a protective effect on OTA-induced damages. In conclusion, this data suggest that OTA contamination in animal feeds and human foods could cause reproductive abnormalities. Our data also indicate that OTA, at least partly by interfering in oxidative stress system, exerts its toxic effects on testes whereas MEL and GgE with antioxidant properties could fairly protect rats against OTA toxic effects.

Does a short abstinence period of only 2 h yield spermatozoa with better motility characteristics than samples collected after 4–7 days? Despite lower semen volume, sperm concentration, total sperm counts and total motile counts, higher percentages of motile spermatozoa with higher velocity and progressiveness were detected in samples obtained after 2 h. Most studies that have assessed the effect of abstinence periods on sperm motility parameters in men with a sperm concentration below 15 million/ml have detected a higher percentage of motile spermatozoa in samples obtained after short abstinence periods. Studies of men with sperm concentrations above 15 million/ml have reported significantly decreased motile sperm counts after 24 h of abstinence compared with longer abstinence periods. This study had a controlled repeated-measures design based on semen samples from 43 male partners, in couples attending for IVF treatment, who had a sperm concentration above 15 million/ml. Data were collected between June 2014 and December 2015 in the Fertility Unit of Aalborg University Hospital (Aalborg, Denmark). Participants provided a semen sample after 4–7 days of abstinence followed by another sample after only 2 h. For both ejaculates, sperm concentration, total sperm counts, motility groups and detailed kinematic parameters were assessed and compared by using the Sperm Class Analyzer (SCA) computer-aided sperm analysis system before and after density gradient selection. The laboratory's local manual method (Makler chamber) was used for comparison. The second raw ejaculate demonstrated lower semen volume (P < 0.0001), sperm concentration (P = 0.003) and sperm counts in all motility sub-groups (P < 0.001) but higher percentages of spermatozoa with higher velocity (P < 0.01), progressiveness (P < 0.001) and hyperactivation (P < 0.001), compared with the first raw ejaculate. The first ejaculate in this study was also used for the IVF/ICSI treatments and therefore only patients with a semen volume ≥2 ml and concentration ≥15 million/ml were included. Further validation in large prospective randomized controlled trials, more purposely directed at normozoospermic males with partners having problems conceiving when there appears to be no female factor, is needed to confirm the potential advantage of using a second semen sample in improving fertilization and pregnancy rates in assisted reproduction. Despite the significantly lower semen volume, sperm concentration and total sperm counts in all motility sub-groups, the significantly higher percentage of spermatozoa with better motility characteristics (velocity, progressiveness and hyperactivation) in the second ejaculate, may provide and allow for a simpler and more effective selection of higher quality spermatozoa. This could prove to be an advantage for ART procedures such as intracytoplasmic sperm injection where a large number of spermatozoa is not needed. It can also be speculated that pooling two consecutive ejaculates obtained after 4–7 days and after 2 h, could be an advantage for intrauterine insemination where a large number of motile spermatozoa are needed. This study was supported by internal grants from the Department of Health Science and Technology, Faculty of Medicine, Aalborg University (Aalborg, Denmark). The SCA^® was provided by a grant from ‘Ferring Pharmaceuticals’ to Aalborg University Hospital (H.I.N). G.V.D.H. is an external senior scientific consultant to Microptic S/L (Barcelona, Spain). H.A. has provided scientific input and presentations for Microptic S/L (Barcelona, Spain) on several occasions. All other authors declare no conflict of interest. N/A.

Hyaluronic acid (HA) plays a prominent role in various aspects of reproductive biology and assisted reproductive technologies (ART). This review describes the multifaceted influence of HA, ranging from primordial germ cell migration, ovarian follicle development, and ovulation in females to sperm structure, physiology, motility, and capacitation in males. In addition, HA also plays an important role in fertilization and promotes embryo implantation by mediating cellular adhesion and communication within the uterus. Against this physiological background, the review examines the current applications of HA in the context of ART. In addition, the article addresses the emerging field of reproductive tissue engineering, where HA‐based hydrogels offer promising perspectives as they can support the development of mature oocytes and spermatogenesis in vitro. Overall, this review highlights the integral role of HA in the intricate mechanisms of reproductive biology and its growing importance for improving ART outcomes and the field of tissue engineering of the reproductive system.

Metabolomic profiling of seminal plasma has been suggested as a possible approach for a fast and non-invasive male infertility evaluation diagnosis. However, metabolomics profiles in normozoospermic men have not been thoroughly investigated, and the influence of ejaculation-abstinence has not been described. To provide interim reference values and find associations between the metabolomics profiles of human seminal plasma and length of ejaculation-abstinence period in normozoospermic men. Semen samples collected after long (4-7 days) and short abstinence (2 h) from 31 normozoospermic males were assessed for routine quality parameters before the seminal plasma was separated by centrifugation. Metabolomics profiles of the seminal plasma were then determined using untargeted Nuclear Magnetic Resonance Spectroscopy. In total, 30 metabolites were identified. Pyruvate showed a higher concentration, while fructose, acetate, choline, methanol, N-acetylglucosamine, O-acetylcarnitine, uridine, and sn-glycero-3-phosphocoline showed lower concentrations in samples collected after short abstinence (vs. long). All metabolites showed lower absolute amounts (volume × concentration) following shorter abstinence. However, the lower sperm concentration in samples collected after short abstinence resulted in higher absolute amounts of pyruvate and taurine per spermatozoa: pyruvate 1.92 (1.12-3.87) vs. 1.29 (0.83-2.62) (P < 0.001) and taurine 0.58 (0.36-0.92) vs. 0.43 (0.28-0.95) (P < 0.05) ng/106 spermatozoa. Simultaneously, there was a higher percentage of progressively motile spermatozoa in samples collected after the short abstinence. The generally lower concentrations of seminal metabolites after short abstinence periods may be related to the shorter time available for secretion and collection of these metabolites by the accessory glands and the epididymides. The concomitant lower number of spermatozoa in the second ejaculate resulted in increased absolute amounts of pyruvate and taurine per spermatozoa, accompanied by increased spermatozoa motility in these samples. The simultaneous increase in percentages of motile spermatozoa and absolute amounts of pyruvate and taurine per spermatozoa after shorter abstinence might indicate that these two metabolites play a more critical role in sperm motility, which should be further investigated in future studies.

Despite the increasing use of computer-aided sperm analysis (CASA) in clinical practice, there is still no golden standard for the type of slide to be used with these systems. Counting chamber depth and loading method, can profoundly influence motility and concentration estimates, thereby undermining the validity and accuracy of CASA. To contribute toward standardized sperm analysis, this study compared different commercially available capillary-filled slides including 10 and 20 µm deep Leja slides (Leja10 and Leja20); 10, 16 and 20 µm deep CellVision slides (CV10, CV16 and CV20); and drop-loaded slides including slide and coverslip (SCS) with a depth of 20.1 µm and the Makler chamber with a depth of 10 µm for sperm analysis when using CASA. The Sperm Class Analyzer (SCA) CASA system was used to assess concentration, motility, and detailed kinematic parameters of 20 normozoospermic human samples using the different chamber slides. Results were evaluated by the repeated measures ANOVA and Intraclass correlation coefficients. The Makler chamber showed significantly (P < 0.05) higher concentrations than other slides. However, there was no significant difference in the percentage of sperm in different motility groups among the slides. CV10, Leja10 and Makler showed significantly higher curvilinear-, average path- and straight-line velocity (VCL, VAP, VSL) values than other slides. In conclusion, despite the objectiveness of the assessments by CASA systems, there are still some discrepancies in the results of sperm concentration, motility and other kinematic parameters when using different commercially available slides. The possible negative influence of the sperm quality misdiagnosis on the selection of treatment strategy in a clinical setting, emphasizes the need for further standardization and quality control of the commercially available chamber slides for use with CASA. Furthermore, this study found more consistent results for capillary-filled chambers compared to drop-loaded slides, suggesting a superior method when using CASA. Abbreviations: DNA: Deoxyribonucleic acid; CASA: Computer-aided semen analysis; SCA: Sperm Class Analyzer; WHO: World Health Organization; CV: CellVision; SCS: Slide and Coverslip; SD: Standard deviation; ANOVA: Analysis of Variance; PR: Progressive; NP: Non-progressive; IMT: Immotile; VCL: Curvilinear velocity; VAP: Average path velocity; VSL: Straight-line velocity; Lin: Linearity; STR: Straightness; WOB: Wobble; ALH: Amplitude of lateral head displacement; BCF: Beat cross frequency