Efficacy of AI-Assisted Personalized Microbiome Modulation by Diet in Functional Constipation: A Randomized Controlled Trial

Background: Currently, medications and behavioral modifications have limited success in the treatment of functional constipation (FC). An individualized diet based on microbiome analysis may improve symptoms in FC. In the present study, we aimed to investigate the impacts of microbiome modulation on chronic constipation. Methods: Between December 2020−December 2021, 50 patients fulfilling the Rome IV criteria for functional constipation were randomized into two groups. The control group received sodium picosulfate plus conventional treatments (i.e., laxatives, enemas, increased fiber, and fluid intake). The study group underwent microbiome analysis and received an individualized diet with the assistance of a soft computing system (Enbiosis Biotechnology®, Sariyer, Istanbul). Differences in patient assessment constipation−quality of life (PAC-QoL) scores and complete bowel movements per week (CBMpW) were compared between groups after 6-weeks of intervention. Results: The mean age of the overall cohort (n = 45) was 31.5 ± 10.2 years, with 88.9% female predominance. The customized diet developed for subjects in the study arm resulted in a 2.5-fold increase in CBMpW after 6-weeks (1.7 vs. 4.3). The proportion of the study group patients with CBMpW > 3 was 83% at the end of the study, and the satisfaction score was increased 4-fold from the baseline (3.1 to 10.7 points). More than 50% improvement in PAC-QoL scores was observed in 88% of the study cohort compared to 40% in the control group (p = 0.001). Conclusion: The AI-assisted customized diet based on individual microbiome analysis performed significantly better compared to conventional therapy based on patient-reported outcomes in the treatment of functional constipation.

Potential associations between alterations in gut microbiome and obesity-related traits after the bariatric surgery

AIM

This study aimed to examine the effects of both obesity and bariatric surgery on gut microbiome, dietary intake, as well as metabolic and inflammatory parameters.

METHODS

All participants (15 with morbid obesity who had bariatric surgery, 8 with morbid obesity and 11 non-obese) were followed-up for a 6-month period with the interviews at baseline (M0), at the end of 3 (M3) and 6 months (M6). Dietary assessment was done, and blood and faecal samples were collected.

RESULTS

Dietary energy and nutrient intakes as well as serum levels glucose, total cholesterol, LDL-cholesterol, and hs-CRP levels decreased by surgery (p<0.05, for each). Participants with morbid obesity had higher levels of Firmicutes and lower levels of Bacteroidetes at M0 compared to non-obese participants. The abundances of Bacteroidetes increased (p=0.02) while Firmicutes decreased (p>0.05) by the surgery, leading a significant decrease in Firmicutes/Bacteroidetes ratio (p=0.01). At sub-phylum level, the abundances of Lactobacillus and Bifidobacterium decreased while Akkermansia increased by the surgery (p<0.01, for each). Although participants who are morbidly obese had a distinct profile according to ß-diversity indices at M0, it became similar with the profile of non-obese participants (p>0.05) at M3 and M6. Similarly, α-diversity indices were lower in subjects with morbid obesity at M0, but became similar to levels in non-obese controls at M6.

CONCLUSION

This study confirmed that bariatric surgery has substantial impacts on gut microbiome composition and diversity, as well as anthropometrical measurements and biochemical parameters, which were associated with the alterations in dietary intake patterns. This article is protected by copyright. All rights reserved.

Presence of OXA-48 Gene in a Clinical Isolate of Lactobacillus rhamnosus

Lactobacilli are part of the microbiota and are also used as probiotics. However, in recent years they have been associated with invasive infections, especially bacteremia. Lactobacillus spp. are usually susceptible to penicillins, macrolides, and carbapenems, but Lactobacillus rhamnosus is intrinsically resistant to glycopeptides. The aim of this study was to determine the antimicrobial susceptibility profile and resistance mechanism of a clinical isolate of L. rhamnosus isolated from 10 sets of blood cultures of the same patient. The isolate was identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (Bruker Daltonics; BD, Bremen, Germany) and 16S rRNA gene sequencing. In vitro susceptibilities to penicillin, ampicillin, imipenem, vancomycin, erythromycin, clindamycin, and linezolid were determined with gradient test strips (bioMérieux, France) on Mueller-Hinton agar plates supplemented with 5% defibrinated horse blood and 20 mg/L β-NAD. The isolate was resistant to vancomycin and imipenem. Polymerase chain reaction test was positive for blaOXA-48 and the presence of this carbapenemase was confirmed by gene sequencing. Although plasmid analysis suggested that the blaOXA-48 is chromosomal in this isolate, it is still an alarming finding for potential transmission of antibiotic resistance genes to other bacteria in the gut. To our knowledge, this is the first report of the presence of blaOXA-48 in a Lactobacillus spp. and has utmost importance as these bacteria are used as probiotics. The isolation of these bacteria from sterile body sites should not go unnoticed.

Characterization of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in Asi (Orontes) River in Turkey

In this study, the presence of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in aquatic environments (the Orontes River and an urban wastewater) was investigated. Fifty-four E. coli strains resistant to cefotaxime were isolated from the river waters and nearby waste water treatment plant and screened for ESBL gene variants, different classes of integrons and sulfonamide resistance genes. The ESBL-producing E. coli strains were further characterized by PhP-typing system, phylogenetic grouping and antimicrobial susceptibility testing. Of the 54 ESBL-producing strains, 14 (25.9%) belonged to four common PhP types and the remaining were of single types. CTX-M type ESBL genes were identified in 68% of the isolates. The most predominant specific CTX-M subtype identified was bla_CTX-M-15 (n = 36), followed by bla_CTX-M-1 (n = 1). None of the isolates were SHV and OXA positive. Most of the ESBL positive isolates (n = 37; 68.5%) were harboring sul gene. This study indicates a widespread distribution of CTX-M-15 producing E. coli strains in the surface waters in part of Turkey, suggesting an aquatic reservoir for ESBL genes.

Characterisation of Phenotypic and Genotypic Antibiotic Resistance Profile of Enterococci from Cheeses in Turkey

The aim of this study was to determine the prevalence of enterococci in cheese samples and to characterize their antimicrobial resistance profiles as well as the associated resistance genes. A total of 139 enterococci were isolated from 99 cheese samples, the isolates were identified as E. faecalis (61.2%), E. faecium (15.1%), E. gallinarum (12.9%), E. durans (5.0%), E. casseliflavis (2.9%) and E. avium (2.9%). The most frequent antimicrobial resistance observed in enterococci isolates was to lincomycin (88.5%), followed by kanamycin (84.2%), gentamycin (low level, 51.1%), rifampin (46.8%) and tetracycline (33.8%). Among the isolates, the frequencies of high level gentamycin and streptomycin resistant enterococci strains were 2.2% and 5.8%, respectively. Apart from the mentioned antibiotics, low levels of resistance to ciprofloxacin, erythromycin and chloramphenicol were found. Moreover no resistance was observed against penicillin and ampicillin. The antimicrobial resistance genes including tetM, tetL, ermB, cat, aph(3’)-IIIa, ant(6)-Ia and aac(6’)-Ieaph(2”)-Ia were found in enterococci from Turkish cheese samples. In the current study, we provided data for antibiotic resistance and the occurrence of resistance genes among enterococci. Regulatory and quality control programs for milk and other dairy products from farms to retail outlets has to be established and strengthened to monitor trends in antimicrobial resistance among emerging food borne pathogens in Turkey.

[Susceptibilities of multidrug-resistant pathogens responsible for complicated skin and soft tissue infections to standard bacteriophage cocktails]

Skin and soft tissue infections (SSTIs) may represent a wide clinical spectrum from cellulitis to high-mortality associated necrotizing fasciitis. Limitations in therapy due to the multiple drug resistance, leads to increase in the morbidity and mortality rates, especially in complicated SSTIs such as diabetic foot, decubitus, and surgical wound infections. Therefore, alternative treatment strategies other than antibiotics are needed in appropriate clinical conditions. "Bacteriophage therapy", which is an old method and has been used as part of standard treatment in some countries such as Georgia and Russia, has again become popular worldwide. The aim of this study was to investigate the in vitro susceptibilities of multidrug-resistant (MDR) pathogens isolated from patients with complicated SSTIs, against standard bacteriophage (phage) cocktails. Six different ready-made phage preparations [Pyophage, Intestiphage, ENKO, SES, Fersisi and Staphylococcal Bacteriophage (Sb)] used in this study have been provided by G. Eliava Institute, Georgia. Because of the absence of ready-made phage preparations for Acinetobacter baumannii and Klebsiella pneumoniae, Φ1-Φ7 and ΦKL1- ΦKL3 phages were used provided from the same institute's phage library, respectively. Isolation and identification of the pathogens from abscess and wound samples of patients with SSTIs were performed by conventional methods and automatized VITEK(®)-2 (bioMerieux, ABD) system. Antimicrobial susceptibility testing was conducted complying CLSI standards' and the bacteria that were resistant to at least two different antibiotic groups were considered as MDR. Accordingly, a total of 33 isolates, nine of them were E.coli (8 ESBL and 1 ESBL + carbapenemase positive); nine were MDR P.aeruginosa; nine were MDR A.baumannii; three were methicillin-resistant Staphylococcus aureus (MRSA) and three were K.pneumoniae (1 ESBL, 1 carbapenemase and 1 ESBL + carbapenemase positive) were included in the study. The phage susceptibilities of the pathogens were performed by using spot test. In the study, 29 (87.9%) out of 33 MDR pathogens were found to be susceptible to at least one of the tested phage/phage preparations. All MRSA (3/3) strains were susceptible to ENKO, SES, Fersisi and Sb phage cocktails, while all A.baumannii isolates (9/9) were susceptible to Φ5 and Φ7 phages. However, two E.coli, one K. pneumoniae and one P.aeruginosa strains were resistant to the all phage preparations tested. Although the clinical use of phages has not been approved yet, except a few Eastern European countries, this study exhibits the potential use of the topical bacteriophage therapy in the treatment of complicated SSTIs caused by MDR pathogens with limited treatment options, such as diabetic foot, decubitus, and surgical wound infections.

Extended-spectrum β-lactamase producing Escherichia coli in hospital wastewaters and sewage treatment plants in Queensland, Australia

We investigated the prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in untreated hospital wastewaters and 2 sewage treatment plants (STPs). A collection of 252 ESBL-producing E. coli isolates from hospital wastewater and STPs were typed and tested for resistance to 17 antimicrobial agents and for the presence of integron-associated integrases (intI gene) and ESBL genes. Eighty-nine percent (n = 176) of the ESBL-producing E. coli strains from hospital wastewater were found in more than 1 sample (common types), with 1 common type accounting for 35% of isolates, found in all samples. These strains were also resistant to up to 9 non-β-lactam antibiotics and showed the same pattern of resistance in all samples. More than 73% of the hospital wastewater isolates possessed SHV-type ESBL as opposed to isolates from STPs that carried only CTX-M-type ESBL genes. The prevalence of the intI gene did not differ between the sources of the isolates. Certain ESBL-producing E. coli were dominant in hospital wastewaters. These strains possessed β-lactamase genes that were different from isolates found in STPs. From a public health point of view, the presence of such a high level of ESBL-producing E. coli strains in hospital wastewaters is of great importance.

Prevalence and pathogenesis of extended-spectrum beta-lactamase producing Escherichia coli causing urinary tract infection in hospitalized patients

A total of 296 E. coli strains isolated from hospitalized patients with urinary tract infection were included in this study. These strains were tested for their resistance to 22 antimicrobial drugs and the presence of ESBLs genes coding for TEM, SHV, OXA, and CTX-M. We further characterized them for their interaction with a renal cell line (A-498) and a gastrointestinal cell line (Caco-2). Strains were also typed using a combination of RAPD-PCR, PhP-typing and phylogenetic grouping. Only eight strains (2.7 %) were confirmed as ESBLs producers. The most common clonal type contained 35 isolates and only two of them were ESBLs producers and both showed a high degree of adhesion to both cell lines but only one was able to translocate in Caco-2 cells. These strains belonged to phylogenetic group B2, were resistant to nine antibiotics and carried CTX-M-type of ESBL. The remaining six strains belonged to single clones with different phylogenetic groups and ESBL genotypes and were resistant to between 12 and 15 antibiotics. They also showed a high rate of adhesion to A-498 cells (19 ± 2 to 35 ± 3 CFU/cell) and all translocated in this cell line. The rate of adhesion of ESBL-producing strains to Caco-2 cells (11 ± 3.4 CFU/cell) was significantly lower than A-498 cells (26 ± 8 CFU/cell) (p = 0.0002) and only four of them translocated in Caco-2 cells. Our results suggest that the ESBL-producing clones of E. coli have a potential to translocate and cause septicemia in hospitalized patients with UTI.

Population structure and uropathogenic virulence-associated genes of faecal Escherichia coli from healthy young and elderly adults

We investigated the population structures of faecal Escherichia coli in 30 healthy young adults (13 males and 17 females) aged between 20 and 45 years and 29 elderly adults (14 females and 15 males) aged between 65 and 77 years. In all, 1566 strains were typed with the PhPlate system and grouped into biochemical phenotypes (BPTs). Strains with shared BPTs were further typed using randomly amplified polymorphic DNA analysis. Forty-four per cent of the strains were shared between two or more age and gender groups. Elders had a significantly higher (P<0.001) number of BPTs (mean±standard error 3.3±0.27) than younger groups (1.82±0.27). Phylogenetic affiliation and virulence-associated genes (VAGs) of the strains showed that more than 80 % of the strains belonging to dominant types belonged to phylogroups B2 and D. Amongst dominant BPTs, phylogenetic group A was significantly associated with females (P<0.0001), and elders were more likely to carry group D (P<0.0124). Elderly males had a higher prevalence of VAGs than young males (P<0.0001) and young females (P<0.0005). We conclude that there is a lower prevalence of E. coli with uropathogenic properties in healthy young adults than in elders.