Alterations of gut microbiota composition in post-finasteride patients: a pilot study.

PURPOSE: Post-finasteride syndrome (PFS) has been reported in a subset of patients treated with finasteride (an inhibitor of the enzyme 5alpha-reductase) for androgenetic alopecia. These patients showed, despite the suspension of the treatment, a variety of persistent symptoms, like sexual dysfunction and cognitive and psychological disorders, including depression. A growing body of literature highlights the relevance of the gut microbiota-brain axis in human health and disease. For instance, alterations in gut microbiota composition have been reported in patients with major depressive disorder. Therefore, we have here analyzed the gut microbiota composition in PFS patients in comparison with a healthy cohort. METHODS: Fecal microbiota of 23 PFS patients was analyzed by 16S rRNA gene sequencing and compared with that reported in ten healthy male subjects. RESULTS: Sexual dysfunction, psychological and cognitive complaints, muscular problems, and physical alterations symptoms were reported in more than half of the PFS patients at the moment of sample collection. The quality sequence check revealed a low library depth for two fecal samples. Therefore, the gut microbiota analyses were conducted on 21 patients. The α-diversity was significantly lower in PFS group, showing a reduction of richness and diversity of gut microbiota structure. Moreover, when visualizing ß-diversity, a clustering effect was found in the gut microbiota of a subset of PFS subjects, which was also characterized by a reduction in Faecalibacterium spp. and Ruminococcaceae UCG-005, while Alloprevotella and Odoribacter spp were increased compared to healthy control. CONCLUSION: Gut microbiota population is altered in PFS patients, suggesting that it might represent a diagnostic marker and a possible therapeutic target for this syndrome.

Steroidogenic machinery in the adult rat colon.

Gastrointestinal function is known to be regulated by steroid molecules produced by the gonads, the adrenal glands and the gut microbiota. However, we have a limited knowledge on the functional significance of local steroid production by gastrointestinal tract tissue. On this basis, we have here evaluated, as a first methodological approach, the expression of steroidogenic molecules and the local levels of key steroids in the male rat colon. Our findings indicate that the colon tissue expresses molecules involved in the early steps of steroidogenesis and in the consecutive synthesis and metabolism of steroid hormones, such as progesterone, testosterone and 17ß-estradiol. In addition, the levels of the steroid hormone precursor pregnenolone and the levels of active metabolites of progesterone and testosterone, such as dihydroprogesterone, tetrahydroprogesterone, dihydrotestosterone and 17ß-estradiol, were higher in colon than in plasma. Higher levels of the androgen metabolite 3α-diol were detected in the colon in comparison with another non-classical steroidogenic tissue, such as the cerebral cortex. These findings suggest the existence of local steroid synthesis and metabolism in the colon, with the production of active steroid metabolites that may impact on the activity of the enteric nervous system and on the composition of the gut microbiota.

Phenylketonuric diet negatively impacts on butyrate production.

BACKGROUND AND AIMS: Phenylalanine (Phe) restricted diet, combined with Phe-free l-amino acid supplementation, is the mainstay of treatment for phenylketonuria (PKU). Being the diet a key factor modulating gut microbiota composition, the aim of the present paper was to compare dietary intakes, gut microbiota biodiversity and short chain fatty acids (SCFAs) production in children with PKU, on low-Phe diet, and in children with mild hyperphenylalaninemia (MHP), on unrestricted diet. METHODS AND RESULTS: We enrolled 21 PKU and 21 MHP children matched for gender, age and body mass index z-score. Dietary intakes, including glycemic index (GI) and glycemic load (GL), and fecal microbiota analyses, by means of denaturing gradient gel electrophoresis (DGGE) and Real-time PCR were assessed. Fecal SCFAs were quantified by gas chromatographic analysis. RESULTS: We observed an increased carbohydrate (% of total energy), fiber and vegetables intakes (g/day) in PKU compared with MHP children (p = 0.047), as well a higher daily GI and GL (maximum p < 0.001). Compared with MHP, PKU showed a lower degree of microbial diversity and a decrease in fecal butyrate content (p = 0.02). Accordingly, two of the most abundant butyrate-producing genera, Faecalibacterium spp. and Roseburia spp., were found significantly depleted in PKU children (p = 0.02 and p = 0.03, respectively). CONCLUSION: The low-Phe diet, characterized by a higher carbohydrate intake, increases GI and GL, resulting in a different quality of substrates for microbial fermentation. Further analyses, thoroughly evaluating microbial species altered by PKU diet are needed to better investigate gut microbiota in PKU children and to eventually pave the way for pre/probiotic supplementations.

Species-specific DNA probe and development of a quantitative PCR assay for the detection of Morganella morganii.

AIMS: To develop a SYBR Green quantitative PCR assay (qPCR) for the specific detection of Morganella morganii, a fish pathogen responsible for the Histamine Fish Poisoning. METHODS AND RESULTS: A new primer set, amplifying a 179-bp fragment of the 16S rRNA gene, was selected for specificity, and 14 M. morganii strains and 32 non-Morganella strains were evaluated. The melting temperature of 84°C was consistently specific for the amplicon. Two standard curves were constructed: the minimum detection sensitivity was 0·563 pg of pure DNA, corresponding to DNA extracted from nine cells of M. morganii. The qPCR assay was evaluated in experiments with seeded fish samples, and the regression coefficient values were calculated. CONCLUSIONS: A highly specific and rapid assay was developed for the detection of M. morganii in tuna fish samples. SIGNIFICANCE AND IMPACT OF THE STUDY: This method represents the first study about the quantification of pathogenic M. morganii in fish products. This approach can be utilized to prevent the presence of this undesirable species in the food chain.

A survey on biotechnological potential and safety of the novel Enterococcus species of dairy origin, E. italicus.

The biotechnological and safety properties of the novel enterococcal species of dairy origin, Enterococcus italicus, were investigated. The strains of the species showed technological characteristics related to their use as adjunct cultures in the production of artisanal cheeses. They were susceptible or poorly resistant to several clinical relevant antibiotics. Moreover, E. italicus strains were associated with low virulence profiles, as verified by screening for the presence of 33 different genes encoding antibiotic resistance and known virulence factors in the genus Enterococcus. From the data obtained, we deduce that the presence of E. italicus strains in cheeses results in a low health risk and that within the species new safe adjunct cultures for the dairy industry could be found.

Salbutamol increases SMN mRNA and protein levels in spinal muscular atrophy cells.

Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder caused by homozygous absence of the survival motor neuron gene (SMN1). All patients have at least one, usually two to four copies of the related SMN2 gene which, however, produce insufficient levels of functional SMN protein due to the exclusion of exon 7 in the majority of SMN2 transcripts. Here, we show that salbutamol, a beta2-adrenoceptor agonist, determines a rapid and significant increase in SMN2-full length mRNA and SMN protein in SMA fibroblasts, predominantly by promoting exon 7 inclusion in SMN2 transcripts. These data, together with previous clinical findings, provide a strong rationale to investigate further the clinical efficacy of salbutamol in SMA patients.

Rapid identification of Enterococcus italicus by PCR with primers targeted to 16S rRNA gene.

AIMS: To develop a species-specific PCR assay with primers targeted to 16S rRNA gene for the identification of Enterococcus italicus, a new species of Enterococcus, involved in the production of Italian cheeses. METHODS AND RESULTS: The type strain of E. italicus (DSM 15952(T) - 16S rRNA gene accession no. AJ582753) and other strains of the species were subjected to a rapid identification by PCR using primer pairs located within the 16S rRNA gene. A species-specific PCR product of approximately 323 bp was obtained after amplification of all E. italicus strains tested. The specificity of the primers was validated with representatives of the most closely related genera and species and a number of other bacterial species. In addition, the technique enabled the recognition of E. italicus from cheeses. CONCLUSIONS: The protocol was highly efficient and sensitive, enabling the identification of E. italicus from cheeses. SIGNIFICANCE AND IMPACT OF THE STUDY: The species-specific PCR offers a reliable and rapid alternative to conventional phenotypic methods for the identification of E. italicus within the heterogeneous genus Enterococcus.

Plasmids from Lactobacillus helveticus: distribution and diversity among natural isolates.

AIMS: To investigate the distribution and the level of diversity of extrachromosomal molecules in Lactobacillus helveticus strains in relation to their different ecological niches. METHODS AND RESULTS: The plasmid profile of 22 Lact. helveticus strains, isolated from five different Italian cheeses, was determined. Among the tested strains, there was a variable presence of plasmids: eight plasmid-free strains and the remaining with several plasmids that could be differentiated on the basis of number and molecular weight. The profiles showed between one and five plasmid bands, which size ranged between 2.3 and 31 kb. Four of these plasmids were further analyzed by restriction digestion and compared with the plasmids from Lact. helveticus ATCC 15009(T). Analyses and comparison of their primary structures and hybridization experiments revealed the presence of different DNA homology groups. CONCLUSIONS: This study indicates that within Lact. helveticus species, there is a high degree of variability in relation to the presence of plasmid molecules. Moreover, the structural diversity found among some of these plasmids allows to hypothesize the presence of different evolutionary lineages. SIGNIFICANCE AND IMPACT OF THE STUDY: Studies on plasmid distribution and diversity should be considered as an essential component in a continuing effort to explore microbial diversity as well as to understand the real role of plasmids in the flow of genetic information in natural bacterial communities.

Proper names in patients with early Alzheimer's disease.

The objective of this study was to seek evidence of the particular sensitivity of proper name retrieval and to check the usefulness of proper names as diagnostic material in the early stages of Alzheimer's disease (AD). Whether a generalized naming deficit is an early symptom of AD it is not yet clear. Previous studies suggest that proper names might be the category of names that is indeed more sensitive to AD. Seventy AD patients (subdivided into "very mild", "mild" and "moderate") and 47 control subjects participated in the study. The performances in two short distinct tests requiring proper name retrieval (Naming People on Definition and Naming Faces), one test of common name retrieval, short (MMSE, 3MS) and long (MODA) batteries for the detection of dementia were compared. Proper name retrieval tests were shown to be more sensitive to early AD than any other tests and batteries that failed to distinguish "very mild" AD from controls. These findings suggest that proper name retrieval tasks might be profitably included in diagnostic tools for the early diagnosis of AD.

Executive deficits appearing in the initial stage of Alzheimer's disease.

The presence of executive deficits has been sought at a stage of Alzheimer's disease where currently used neuropsychological batteries could not yet distinguish Alzheimer's patients from normal age- and education-matched controls. This study shows that, at this early stage, those patients that 6 months later are found to show clear signs of Alzheimer's had been significantly worse than normal controls in an executive function task adapted from the Brown-Peterson procedure.

When living things and other 'sensory quality' categories behave in the same fashion: a novel category specificity effect.

In this study, the performance on semantic tests of five patients with a diagnosis of probable herpes simplex encephalitis was examined. Only one of the patients, MU, showed a marked category-specific deficit for living things, unlike the other patients. Results which closely mirrored those obtained with the category living things were found in each of the five patients for the other categories, edible substances, materials, and liquids, selected for a priori theoretical reasons. The processing of these additional categories was investigated with tasks involving naming abilities in different modalities, matching to sample, and questionnaires exploring the status of the patients' knowledge about the semantic features of both living things and exemplars of novel 'sensory quality' categories. MU showed in all tasks a comparable impairment for both living things and the other three new categories, in spite of a performance closely equivalent to that of the other four patients with man-made artefacts. This finding supports an explanation of MU's performance in terms of an impairment relating to categories highly dependent on the sensory quality of stimuli. In addition, his difficulty involved all aspects of the processing of the impaired categories.

A componential analysis of visual object recognition deficits in patients with herpes simplex virus encephalitis.

Five patients with a diagnosis of Herpes Simplex Virus Encephalitis (HSVE) underwent neuropsychological assessment to explore the integrity of their visual perceptual abilities. Selective deficits affecting different levels of the recognition processing were found; impaired recognition abilities were also influenced by selective task requirements, which resulted either in facilitatory or constraining effects on patients' performance. A theoretical model of object recognition (Humphreys & Riddoch, 1987) was taken into account to explain patients' performance. Further, the role of specific components of visual processing was evidenced in explaining the performance of patients affected by HSVE.

Proper names in the early stages of Alzheimer's disease.

A short proper name retrieval test was found to discriminate between unselected subjects and age- and education- matched patients affected by Alzheimer's type dementia at a stage where the Mini-Mental State Examination could not detect a difference between these groups. The proper name retrieval task also compared favorably with the 3MS, a more sensitive, modified version of the MMSE. These findings suggest that proper name retrieval could be used to an advantage and become a routine component of short batteries for the early detection of Alzheimer's disease.

Memory for/and execution of future intentions: evidence from patients with Herpes Simplex Encephalitis.

Prospective remembering was studied in a group of patients who suffered from Herpes Simplex Encephalitis (HSE). All patients showed a marked deficit in executing intentions for future actions under all the given constraints. The deficit extended to both time- and event-based intentions. The analysis of errors showed somewhat different patterns and some dissociations with evidence for selective preservation or damage to specific components involved in prospective remembering. These patients, in fact, may fail because of a difficulty in taking into account all given constraints or in activating stored intentions and in forming intentions or in remembering the content of the actions. Time- and event-based tasks seem to show different sources of errors also in the same patient.

Dichaptic scanning of Braille letters by skilled blind readers: lateralization effects.

Dichaptic scanning of Braille letters was studied in 14 skilled blind readers, using Posner's paradigm. A right-hand (left-hemisphere) advantage was found when letters could be matched on the basis of their names (Name Identity Condition), a genuinely linguistic task, while no effects of lateralization appeared when matching could be performed on the basis of perceptual identity (Perceptual Identity Condition) or on "Different" responses. This result provides information about the cerebral lateralization of Braille reading and casts doubts about the current claim that linguistic material, when presented in the tactile modality, is initially analysed in a spatial code by the right hemisphere.