D-lactic acidosis in humans: systematic literature review

Factors associated with D-lactic acidosis in pediatric intestinal failure: A case-control study

BACKGROUND

D-lactic acidosis (DLA) is a serious complication of short bowel syndrome (SBS) in children with intestinal failure (IF). Malabsorbed carbohydrates are metabolized by bacteria in the intestine to D-lactate which can lead to metabolic acidosis and neurologic symptoms.

METHODS

A retrospective chart review was performed in children ≤18 years old with SBS who had one of the following criteria: unexplained metabolic acidosis, neurologic signs or symptoms, history of antibiotic therapy for small bowel bacterial overgrowth, or high clinical suspicion of DLA. Cases had serum D-lactate concentration >0.25 mmol/L; controls with concentrations ≤0.25 mmol/L.

RESULTS

Of forty-six children, median age was 3.16 (interquartile range (IQR): 1.98, 5.82) years, and median residual bowel length was 40 (IQR: 25, 59) cm. There were 23 cases and 23 controls. Univariate analysis showed that cases had significantly lower median bicarbonate (19 vs. 24 mEq/L, p = 0.001), higher anion gap (17 vs. 14 mEq/L, p < 0.001) and were less likely to be receiving parenteral nutrition, compared with children without DLA. Multivariable analysis identified midgut volvulus, history of intestinal lengthening procedure, and anion gap as significant independent risk factors. Midgut volvulus was the strongest independent factor associated with DLA (adjusted odds ratio = 17.1, 95% CI: 2.21, 133, p = 0.007).

CONCLUSION

DLA is an important complication of pediatric IF due to SBS. Patients with IF, particularly those with history of midgut volvulus, having undergone intestinal lengthening, or with anion gap acidosis, should be closely monitored for DLA.

Metabolic and Nutritional Issues after Lower Digestive Tract Surgery: The Important Role of the Dietitian in a Multidisciplinary Setting

Many patients undergo small bowel and colon surgery for reasons related to malignancy, inflammatory bowel disease (IBD), mesenteric ischemia, and other benign conditions, including post-operative adhesions, hernias, trauma, volvulus, or diverticula. Some patients arrive in the operating theatre severely malnourished due to an underlying disease, while others develop complications (e.g., anastomotic leaks, abscesses, or strictures) that induce a systemic inflammatory response that can increase their energy and protein requirements. Finally, anatomical and functional changes resulting from surgery can affect either nutritional status due to malabsorption or nutritional support (NS) pathways. The dietitian providing NS to these patients needs to understand the pathophysiology underlying these sequelae and collaborate with other professionals, including surgeons, internists, nurses, and pharmacists. The aim of this review is to provide an overview of the nutritional and metabolic consequences of different types of lower gastrointestinal surgery and the role of the dietitian in providing comprehensive patient care. This article reviews the effects of small bowel resection on macronutrient and micronutrient absorption, the effects of colectomies (e.g., ileocolectomy, low anterior resection, abdominoperineal resection, and proctocolectomy) that require special dietary considerations, nutritional considerations specific to ostomized patients, and clinical practice guidelines for caregivers of patients who have undergone a surgery for local and systemic complications of IBD. Finally, we highlight the valuable contribution of the dietitian in the challenging management of short bowel syndrome and intestinal failure.

Antimicrobial and Mycotoxin Reducing Properties of Lactic Acid Bacteria and Their Influence on Blood and Feces Parameters of Newborn Calves

The aim of this study was to evaluate the influence of in acid whey (AW) multiplied Lactiplantibacillus plantarum LUHS135 (L.pl135), Lacticaseibacillus paracasei LUHS244 (L.pc244), and their biomass combination on newborn calves' feces and blood parameters. Additionally, the antimicrobial and mycotoxin-reducing properties and the resistance to antibiotics of the tested lactic acid bacteria (LAB) strains were analyzed. In order to ensure effective biomass growth in AW, technological parameters for the supplement preparation were selected. Control calves were fed with a standard milk replacer (SMR) and treated groups (from the 2nd day of life until the 14th day) were supplemented with 50 mL of AWL.pl135, AWL.pc244, and AWL.pl135×L.pc244 (25 mL AWL.pl135 + 25 mL AWL.pc244) in addition to SMR. It was established that L.pl135 and L.pc244 possess broad antimicrobial activities, are non-resistant to the tested antibiotics, and reduce mycotoxin concentrations in vitro. The optimal duration established for biomass growth was 48 h (LAB count higher than 7.00 log10 CFU mL-1 was found after 48 h of AW fermentation). It was established that additional feeding of newborn calves with AWL.pl135, AWL.pc244, and AWL.pl135×L.pc244 increased lactobacilli (on average by 7.4%), and AWL.pl135 and AWL.pc244 reduced the numbers of Enterobacteriaceae in calves' feces. The tested supplements also reduced the lactate concentration (on average, by 42.5%) in calves' blood. Finally, the tested supplements had a positive influence on certain health parameters of newborn calves; however, further research is needed to validate the mechanisms of the beneficial effects.

Nutrition and Intestinal Rehabilitation of Children With Short Bowel Syndrome: A Position Paper of the ESPGHAN Committee on Nutrition. Part 2: Long-Term Follow-Up on Home Parenteral Nutrition

Short bowel syndrome (SBS) is the leading cause of intestinal failure (IF) in children. The preferred treatment for IF is parenteral nutrition which may be required until adulthood. The aim of this position paper is to review the available evidence on managing SBS and to provide practical guidance to clinicians dealing with this condition. All members of the Nutrition Committee of the European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) contributed to this position paper. Some renowned experts in the field joined the team to guide with their expertise. A systematic literature search was performed from 2005 to May 2021 using PubMed, MEDLINE, and Cochrane Database of Systematic Reviews. In the absence of evidence, recommendations reflect the expert opinion of the authors. Literature on SBS mainly consists of retrospective single-center experience, thus most of the current papers and recommendations are based on expert opinion. All recommendations were voted on by the expert panel and reached >90% agreement. This second part of the position paper is dedicated to the long-term management of children with SBS-IF. The paper mainly focuses on how to achieve intestinal rehabilitation, treatment of complications, and on possible surgical and medical management to increase intestinal absorption.

Early detection of plasma d-lactate: Toward a new highly-specific biomarker of bacteraemia?

Background

Bloodstream infections are a leading cause of mortality. Their detection relies on blood cultures (BCs) but time to positivity is often between tens of hours and days. d-lactate is a metabolite widely produced by bacteria but very few in human. We aimed to evaluate d-lactate, d-lactate/l-lactate ratio and d-lactate/total lactate ratio in plasma as potential early biomarkers of bacteraemia on a strictly biological standpoint.

Methods

A total of 228 plasma specimens were collected from patients who had confirmed bacteraemia (n = 131) and healthy outpatients (n = 97). Specific l-lactate and d-lactate analyses were performed using enzymatic assays and analytical performances of d-lactate, d-lactate/total lactate and d-lactate/l-lactate ratios for the diagnosis of bacteraemia were assessed.

Results

A preliminary in vitro study confirmed that all strains of Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus were able to produce d-lactate at significant levels. In patients, plasma d-lactate level was the most specific biomarker predicting a bacteraemia profile with a specificity and predictive positive value of 100% using a cut-off of 131 μmol.L^-1. However, sensitivity and negative predictive value were rather low, estimated at 31% and 52%, respectively. d-lactate displayed an Area Under Receiver Operating Characteristic (AUROC) curve of 0.696 with a P value < 0.0001. There was no difference of d-lactate levels between BCs bottles positive for Gram-positive or Gram-negative bacteria (p = 0.55).

Conclusion

d-lactate shows promise as a specific early biomarker of bacterial metabolism. The development of rapid automated assays could raise clinical applications for infectious diseases diagnosis including early bacteraemia prediction.

Effects of Zinc Supplementation in Mitigating the Harmful Effects of Chronic Cadmium Exposure in a Zebrafish Model

Cadmium (Cd) is a heavy metal that is highly toxic to living organisms, including humans. But the dietary zinc (Zn) supplements play critical role in minimizing or preventing Cd poisoning, without any side effects. The underlying mechanisms, however, have not been thoroughly investigated. Therefore, in this study, we investigated the use of Zn as a protection against Cd toxicity in zebrafish models. The obtained results confirmed the levels of antioxidant enzymes and supported the synergistic effects of Zn in reducing Cd toxicity. The lipid, carbohydrate, and protein concentrations in the liver tissue have also been negatively impacted by Cd; however, treatment with Zn has lessened these adverse effects. Furthermore, the level of 8-hydroxy-2' -deoxyguanosine (8-OHdG), caspase-3 also confirms the protective effects of Zn in reducing DNA damage caused by Cd. The results of this study demonstrate that a Zn supplement can lessen the harmful effects of Cd in zebrafish model.

What is the Accuracy of a Rapid Strip Test That Detects D-lactic Acid in Synovial Fluid for the Diagnosis of Periprosthetic Joint Infections?

BACKGROUND

D-lactic acid is a specific marker produced almost exclusively by bacterial species; thus, the appearance of this marker in synovial fluid may indicate periprosthetic joint infection (PJI). Recently, studies have investigated the accuracy of enzyme-linked laboratory tests that detect D-lactic acid in synovial fluid to diagnose PJI. However, to our knowledge, no studies have determined the usefulness of rapid strip tests that detect D-lactic acid in synovial fluid in the diagnosis of PJI.

QUESTIONS/PURPOSES

(1) What is the best cutoff value for the rapid D-lactic acid strip test for diagnosing PJI? (2) What are the diagnostic accuracies (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) of the rapid D-lactic acid strip test and two different rapid leukocyte esterase (LE) strip tests?

METHODS

This prospective study enrolled 157 patients who underwent revision THA or TKA from May 2021 to February 2022 at a single orthopaedic center. Seventy percent (110 of 157) were eligible for analysis; 10% of these patients (15 of 157) were excluded based on the exclusion criteria (causes of revisions and additional comorbidities that may interfere with the results), and 20% (32 of 157) of the synovial fluid samples could not be tested (dry taps and blood-contaminated samples that could not be centrifuged). We performed the following off-label diagnostic tests on synovial fluid samples collected from all patients: the D-lactic acid strip test (QuantiQuick TM , BioAssay System), two different LE strip tests (10 EA from ARKRAY and BM 10 from BioMaxima). Differently colored strips were marked with symbols (from [-] to [++++] for D-lactic acid and from [-] to [+++] for LE tests) according to the manufacturers' instructions. For the LE tests, results were different for (++), which corresponds to a minimal value of 250 leu/mL for 10 EA and 125 leu/mL for BM 10 tests. The diagnostic standard for the presence or absence of PJI in this study was the International Consensus Meeting (ICM) 2018 criteria; based on these criteria (without the application of an LE test as a minor criterion), all patients were assessed and divided into two groups. Patients who did not meet the criteria for PJI and underwent revision for aseptic loosening, implant malposition, instability, or implant damage were included in the aseptic revision total joint arthroplasty group (68 patients). Patients with a fistula penetrating the joint, those with two positive culture results of the same pathogen, or those with ≥ 6 points according to ICM 2018 minor criteria were enrolled in the PJI group (42 patients). To ascertain the best cutoff value for the rapid D-lactic acid and both LE strip tests for diagnosing PJI, we used collected results, generated a receiver operating characteristic curve, and calculated the Youden index. To determine the accuracies of the diagnostic tests, we calculated their sensitivities, specificities, PPVs, and NPVs against the diagnostic standard (the ICM 2018 criteria).

RESULTS

The best cutoff value for D-lactic acid was 22.5 mg/L, which corresponded to a reading of (+) on the test strip. For D-lactic acid, in the diagnosis of PJI, the sensitivity was 83% (95% confidence interval [CI] 68% to 92%) and specificity was 100% (95% CI 93% to 100%). For both LE strip tests, the best cutoff value was the same as that proposed in the ICM 2018 criteria. For LE (10 EA), the sensitivity was 81% (95% CI 66% to 91%) and specificity was 99% (95% CI 91% to 100%); for LE (BM 10), sensitivity was 81% (95% CI 65% to 91%) and specificity was 97% (95% CI 89% to 100%).

CONCLUSION

A rapid off-label D-lactic acid strip test is valuable for diagnosing PJI. The results of this study indicate very good accuracy with comparable sensitivity and specificity for both LE strip tests. The usefulness of the test in a group of patients with chronic inflammatory diseases and the reproducibility of the reading by different researchers were not analyzed in this study and require further investigations. Before a rapid D-lactic strip test is routinely used for diagnosing PJI, multicenter studies on a larger group of patients should be conducted.Level of Evidence Level II, diagnostic study.

Probiogenomic In-Silico Analysis and Safety Assessment of Lactiplantibacillus plantarum DJF10 Strain Isolated from Korean Raw Milk

The whole genome sequence of Lactiplantibacillus plantarum DJF10, isolated from Korean raw milk, is reported, along with its genomic analysis of probiotics and safety features. The genome consists of 29 contigs with a total length of 3,385,113 bp and a GC content of 44.3%. The average nucleotide identity and whole genome phylogenetic analysis showed the strain belongs to Lactiplantibacillus plantarum with 99% identity. Genome annotation using Prokka predicted a total of 3235 genes, including 3168 protein-coding sequences (CDS), 59 tRNAs, 7 rRNAs and 1 tmRNA. The functional annotation results by EggNOG and KEGG showed a high number of genes associated with genetic information and processing, transport and metabolism, suggesting the strain's ability to adapt to several environments. Various genes conferring probiotic characteristics, including genes related to stress adaptation to the gastrointestinal tract, biosynthesis of vitamins, cell adhesion and production of bacteriocins, were identified. The CAZyme analysis detected 98 genes distributed under five CAZymes classes. In addition, several genes encoding carbohydrate transport and metabolism were identified. The genome also revealed the presence of insertion sequences, genomic islands, phage regions, CRISPR-cas regions, and the absence of virulence and toxin genes. However, the presence of hemolysin and antibiotic-resistance-related genes detected in the KEGG search needs further experimental validation to confirm the safety of the strain. The presence of two bacteriocin clusters, sactipeptide and plantaricin J, as detected by the BAGEL 4 webserver, confer the higher antimicrobial potential of DJF10. Altogether, the analyses in this study performed highlight this strain's functional characteristics. However, further in vitro and in vivo studies are required on the safety assurance and potential application of L. plantarum DJF10 as a probiotic agent.

High-Anion-Gap Metabolic Acidosis During a Prolonged Hospitalization Following Perforated Diverticulitis: An Educational Case Report

Rationale:

The metabolic acidoses are generally separated into 2 categories on the basis of an anion gap calculation: high-anion-gap and normal anion-gap metabolic acidosis. When a high-anion-gap metabolic acidosis (HAGMA) is not clearly explained by common etiologies and routine confirmatory testing, specialized testing can definitively establish rare diagnoses such as 5-oxoproline, d-lactate accumulation, or diethylene glycol toxicity.

Presenting Concerns of the Patient:

A 56-year-old woman had a prolonged hospital admission following perforated diverticulitis requiring sigmoid resection. Her hospitalization was complicated by feculent peritonitis and surgical wound dehiscence needing prolonged broad-spectrum antibiotics and wound debridements. She developed acute kidney injury and HAGMA in the hospital.

Diagnoses:

Chart review showed that she received a large cumulative dose of acetaminophen during her hospital stay. Laboratory studies showed markedly increased serum 5-oxoproline causing HAGMA.

Interventions (Including Prevention and Lifestyle):

Patient was admitted to the intensive care unit and treated with N-acetylcysteine and renal replacement therapy.

Outcomes:

After admission to the intensive care unit, the patient continued to require vasopressor and ventilatory support for septic shock and a ventilator-associated pneumonia. After an initial recovery and resolution of her HAGMA, she subsequently suffered recurrent aspirations which were fatal.

Teaching points:

Integrated genome-based assessment of safety and probiotic characteristics of Lactiplantibacillus plantarum PMO 08 isolated from kimchi

Lactiplantibacillus plantarum PMO 08 has been used as a probiotic starter culture for plant-based fermented beverages, with various health-promoting effects such as cholesterol-lowering and anti-inflammatory activities. This study aimed to analyze the genome sequence of Lp. plantarum PMO 08 and identify its safety and probiotic characteristics at the genomic level. For this, complete genome sequencing was conducted to investigate the genes associated with risk and probiotic characteristics by using Pacbio combined with Illumina HiSeq. This bacterial strain has one circular chromosome of 3,247,789 bp with 44.5% G + C content and two plasmids of 50,296 bp with 39.0% G + C content and 19,592 bp with 40.5% G + C content. Orthologous average nucleotide identity analysis showed that PMO 08 belongs to the Lp. plantarum group with 99.14% similarity to Lp. plantarum WCFS1. No deleterious genes were determined in the virulence factor analysis, and no hemolysin activity or secondary bile salt synthesis were detected in vitro test. In the case of antibiotic resistance analysis, PMO 08 was resistant to ampicillin in vitro test, but these genes were not transferable. In addition, the strain showed same carbohydrate utilization with Lp. plantarum WCFS1, except for mannopyranoside, which only our strain can metabolize. The strain also harbors a gene for inositol monophosphatase family protein related with phytate hydrolysis and have several genes for metabolizing various carbohydrate which were rich in plant environment. Furthermore, in probiotic characteristics several genes involved in phenotypes such as acid/bile tolerance, adhesion ability, and oxidative stress response were detected in genome analysis. This study demonstrates that Lp. plantarum PMO 08 harbors several probiotic-related genes (with no deleterious genes) and is a suitable probiotic starter for plant-based fermentation.

Whole genome sequencing for the risk assessment of probiotic lactic acid bacteria

Probiotic bacteria exhibit beneficial effects on human and/or animal health, and have been widely used in foods and fermented products for decades. Most probiotics consist of lactic acid bacteria (LAB), which are used in the production of various food products but have also been shown to have the ability to prevent certain diseases. With the expansion of applications for probiotic LAB, there is an increasing concern with regard to safety, as cases with adverse effects, i.e., severe infections, transfer of antimicrobial resistance genes, etc., can occur. Currently, in vitro assays remain the primary way to assess the properties of LAB. However, such methodologies are not meeting the needs of strain risk assessment on a high-throughput scale, in the context of the evolving concept of food safety. Analyzing the complete genetic information, including potential virulence genes and other determinants with a negative impact on health, allows for assessing the safe use of the product, for which whole-genome sequencing (WGS) of individual LAB strains can be employed. Genomic data can also be used to understand subtle differences in the strain level important for beneficial effects, or protect patents. Here, we propose that WGS-based bioinformatics analyses are an ideal and cost-effective approach for the initial in silico microbial risk evaluation, while the technique may also increase our understanding of LAB strains for food safety and probiotic property evaluation.

D-Lactic Acidosis in Short Bowel Syndrome

D-lactic acidosis (D-LA) is closely associated with short bowel syndrome (SBS). Decreased intestinal absorption results in the delivery of carbohydrates to the colon, where the fermentation by colonic flora leads to D-LA. Systemic absorption of D-lactic acid results in anion-gap metabolic acidosis (AGMA), LA, and neurologic symptoms. In this report, we describe the case of a 43-year-old man with Crohn’s disease (CD) and bowel resection who presented with abdominal pain and slurred speech. He was found to have AGMA and persistent LA despite receiving intravenous fluids, which improved after carbohydrate restriction. A high index of suspicion for D-LA should be maintained when encountering patients who have undergone bowel resection and with unexplained AGMA.

Roles of transient receptor potential channel 6 in glucose-induced cardiomyocyte injury

BACKGROUND

Diabetic cardiomyopathy (DCM) is a serious complication of end-stage diabetes that presents symptoms such as cardiac hypertrophy and heart failure. The transient receptor potential channel 6 (TRPC6) protein is a very important selective calcium channel that is closely related to the development of various cardiomyopathies.

AIM

To explore whether TRPC6 affects cardiomyocyte apoptosis and proliferation inhibition in DCM.

METHODS

We compared cardiac function and myocardial pathological changes in wild-type mice and mice injected with streptozotocin (STZ), in addition to comparing the expression of TRPC6 and P-calmodulin-dependent protein kinase II (P-CaMKII) in them. At the same time, we treated H9C2 cardiomyocytes with high glucose and then evaluated the effects of addition of SAR, a TRPC6 inhibitor, and KN-93, a CaMKII inhibitor, to such H9C2 cells in a high-glucose environment.

RESULTS

We found that STZ-treated mice had DCM, decreased cardiac function, necrotic cardiomyocytes, and limited proliferation. Western blot and immunofluorescence were used to detect the expression levels of various appropriate proteins in the myocardial tissue of mice and H9C2 cells. Compared to those in the control group, the expression levels of the apoptosis-related proteins cleaved caspase 3 and Bax were significantly higher in the experimental group, while the expression of the proliferation-related proteins proliferating cell nuclear antigen (PCNA) and CyclinD1 was significantly lower. In vivo and in vitro, the expression of TRPC6 and P-CaMKII increased in a high-glucose environment. However, addition of inhibitors to H9C2 cells in a high-glucose environment resulted in alleviation of both apoptosis and proliferation inhibition.

CONCLUSION

The inhibition of apoptosis and proliferation of cardiomyocytes in a high-glucose environment may be closely related to activation of the TRPC6/P-CaMKII pathway.

The Impacts of Lactiplantibacillus plantarum on the Functional Properties of Fermented Foods: A Review of Current Knowledge

One of the most varied species of lactic acid bacteria is Lactiplantibacillus plantarum (Lb. plantarum), formerly known as Lactobacillus plantarum. It is one of the most common species of bacteria found in foods, probiotics, dairy products, and beverages. Studies related to genomic mapping and gene locations of Lb. plantarum have shown the novel findings of its new strains along with their non-pathogenic or non-antibiotic resistance genes. Safe strains obtained with new technologies are a pioneer in the development of new probiotics and starter cultures for the food industry. However, the safety of Lb. plantarum strains and their bacteriocins should also be confirmed with in vivo studies before being employed as food additives. Many of the Lb. plantarum strains and their bacteriocins are generally safe in terms of antibiotic resistance genes. Thus, they provide a great opportunity for improving the nutritional composition, shelf life, antioxidant activity, flavour properties and antimicrobial activities in the food industry. Moreover, since some Lb. plantarum strains have the ability to reduce undesirable compounds such as aflatoxins, they have potential use in maintaining food safety and preventing food spoilage. This review emphasizes the impacts of Lb. plantarum strains on fermented foods, along with novel approaches to their genomic mapping and safety aspects.

Results of an International Survey on Feeding Management in Infants With Short Bowel Syndrome-Associated Intestinal Failure

OBJECTIVES

Short bowel syndrome (SBS) is a complex and rare condition (incidence 1200/100,000 live births) that requires a multidisciplinary team approach to management. In January 2019, the first European Reference Network on Rare and Inherited Congenital Anomalies (ERNICA) Intestinal Failure (IF) workshop was held. Several questions about the strategies used in managing IF associated with SBS were devised. The aim of our study was to collect data on the enteral feeding strategies adopted by the ERNICA centres.

METHODS

A questionnaire (36 questions) about strategies used to introduce enteral nutrition post-operatively and start complementary food/solids in infants with SBS associated IF was developed and sent to 24 centres in 15 countries that participated in the ERNICA-IF workshop. The answers were collated and compared with the literature.

RESULTS

There was a 100% response rate. In infants, enteral nutrition was introduced as soon as possible, ideally within 24-48 hours post-small intestinal surgical resection. In 10 of 24 centres, bolus feeding was used, in nine continuous, and in five a combination of both. Twenty-three centres used mothers' own milk as the first choice of feed with extensively hydrolysed feed, amino acid-based feed, donor human milk or standard preterm/term formula as the second choice. Although 22 centres introduced complementary/solid food by 6 months of age, food choice varied greatly between centres and appeared to be culturally based.

CONCLUSIONS

There is diversity in post-surgical enteral feeding strategies among centres in Europe. Further multi-centre studies could help to increase evidence-based medicine and management on this topic.

Pediatric intestinal failure and the microbiome

Neonatal intestinal failure is a complex medical condition that is associated with the need for long term parenteral nutrition and its associated complications. The microbiome in this diseased state is different from what is now understood to be a healthy microbiome. The effect of this dysbiotic microbiome on the complications of intestinal failure are only starting to be understood. The ability to modulate the microbiome with enteral/parenteral nutrients, as well probiotics to a healthier state, is an exciting opportunity that holds promise.

Few-Layer MoS2 Photodetector Arrays for Ultrasensitive On-Chip Enzymatic Colorimetric Analysis

Enzymatic colorimetric analysis of metabolites provides signatures of energy conversion and biosynthesis associated with disease onsets and progressions. Miniaturized photodetectors based on emerging two-dimensional transition metal dichalcogenides (TMDCs) promise to advance point-of-care diagnosis employing highly sensitive enzymatic colorimetric detection. Reducing diagnosis costs requires a batched multisample assay. The construction of few-layer TMDC photodetector arrays with consistent performance is imperative to realize optical signal detection for a miniature batched multisample enzymatic colorimetric assay. However, few studies have promoted an optical reader with TMDC photodetector arrays for on-chip operation. Here, we constructed 4 × 4 pixel arrays of miniaturized molybdenum disulfide (MoS₂) photodetectors and integrated them with microfluidic enzyme reaction chambers to create an optoelectronic biosensor chip device. The fabricated device allowed us to achieve arrayed on-chip enzymatic colorimetric detection of d-lactate, a blood biomarker signifying the bacterial translocation from the intestine, with a limit of detection that is 1000-fold smaller than the clinical baseline, a 10 min assay time, high selectivity, and reasonably small variability across the entire arrays. The enzyme (Ez)/MoS₂ optoelectronic biosensor unit consistently detected d-lactate in clinically important biofluids, such as saliva, urine, plasma, and serum of swine and humans with a wide detection range (10^-3-10³ μg/mL). Furthermore, the biosensor enabled us to show that high serum d-lactate levels are associated with the symptoms of systemic infection and inflammation. The lensless, optical waveguide-free device architecture should readily facilitate development of a monolithically integrated hand-held module for timely, cost-effective diagnosis of metabolic disorders in near-patient settings.

The Quality of Wheat Bread With Ultrasonicated and Fermented By-Products From Plant Drinks Production

During plant-based drinks production a significant amount of valuable by-products (BPs) is obtained. The valorization of BPs is beneficial for both the environment and the food industry. The direct incorporation of the fermented and/or ultrasonicated almond, coconut, and oat drinks production BPs in other food products, such as wheat bread (WB) could lead to the better nutritional value as well as quality of WB. Therefore, in this study, various quantities (5, 10, 15, and 20%) of differently treated [ultrasonicated (37 kHz) or fermented with Lacticaseibacillus casei LUHS210] almond, coconut, and oat drinks preparation BPs were used in wheat bread (WB) formulations. Microbiological and other quality parameters (acidity, color, specific volume, porosity, moisture content, overall acceptability) as well as bread texture hardness during the storage and acrylamide content in the WB were evaluated. Among the fermented samples, 12-h-fermented almond and oat, as well as 24-h-fermented coconut drinks preparation BPs (pH values of 2.94, 2.41, and 4.50, respectively; total enterobacteria and mold/yeast were not found) were selected for WB production. In most cases, the dough and bread quality parameters were significantly (p ≤ 0.05) influenced by the BPs used, the treatment of the BPs, and the quantity of the BPs. The highest overall acceptability of the WB prepared with 20% fermented almond drink preparation by-product (AP), 15% fermented oat drink preparation by-product (OP), and 15% ultrasonicated OP was established. After 96 h of storage, the lowest hardness (on average, 1.2 mJ) of the breads prepared with 5% fermented AP, coconut drink preparation by-product (CP), and OP and ultrasonicated CP was found. The lowest content of acrylamide in the WB prepared with OP was found (on average, 14.7 μg/kg). Finally, 15% fermented OP could be safely used for WB preparation because the prepared bread showed high overall acceptability, as well as low acrylamide content.

Combination of Extrusion and Fermentation with Lactobacillus plantarum and L. uvarum Strains for Improving the Safety Characteristics of Wheat Bran

Processed wheat bran (W) is of great importance for food and feed. Consequently, the biosafety of W should be evaluated and improved with valorisation strategies. This study tested a design combining extrusion (at temperature of 115 and 130 °C; screw speeds of 16, 20, and 25 rpm) and fermentation with Lactobacillus plantarum and L. uvarum strains for the valorisation of W to provide safer food and feed stock. The influence of different treatments on biogenic amine formation, mycotoxin content, and free amino acids, as well as acidity, microbiological parameters, and sugar concentration, were analysed. This research showed that a combination of extrusion and fermentation with selected strains can change several aspects of W characteristics. There was a significant effect of applied treatments on acidity and the microbiological parameters of W, as well as biogenic amines content. The lowest total mycotoxin concentration (29.8 µg/kg) was found in extruded (130 °C; 25 rpm) and fermented with L. uvarum sample. Finally, the combination of the abovementioned treatments can be confirmed as a prospective innovative pre-treatment for W, capable of potentially enhancing their safety characteristics and composition.

Recurrent Encephalopathy and Severe Anion Gap Metabolic Acidosis in a Patient with Short Bowel: It Is D-Lactic Acidosis

D-lactic acidosis is a rare and potentially underrecognized condition in patients with short bowel syndrome. We present the case of a 61-year-old female with a history of an ileojejunal bypass at age 18 who presented to hospital with acute-onset encephalopathy, ataxia, and severe anion gap metabolic acidosis (AGMA). On initial investigations there were no identifiable etiologies for the AGMA. Further history revealed that she had been experiencing these symptoms on a recurrent basis for the past 40 years. An oral carbohydrate load was given to the patient in hospital which reproduced her symptoms and the AGMA. A serum D-lactate level returned elevated several weeks later. A 2-month follow-up revealed that all her symptoms had ceased with limitation of carbohydrates to 150 g per day. Patients with short bowel syndrome are susceptible to developing D-lactic acidosis due to the large carbohydrate loads that are delivered to the colon, where they are then metabolized. Due to its rarity, it is likely that there is a delay in recognition of this condition. This case report describes a common clinical presentation of this rare condition and describes the pathophysiology, diagnosis, and management of D-lactic acidosis in small bowel syndrome.

Nutritional and pharmacological strategy in children with short bowel syndrome

Short bowel syndrome in neonates is a severe and life-threatening disease after a major loss of small bowel with or without large bowel. Intestinal adaptation, by which the organism tries to restore digestive and absorptive capacities, is entirely dependent on stimulation of the active enterocytes by enteral nutrition. This review summarizes recent knowledge about the pathophysiologic consequences after the loss of different intestinal parts and outlines the options for enteral nutrition and pharmacological therapies to support the adaptation process.

Development of a selective three-dimensional HPLC system for enantiomer discriminated analysis of lactate and 3-hydroxybutyrate in human plasma and urine

For the enantiomer discriminated determination of lactate (LA) and 3-hydroxybutyrate (3HB) in various complicated samples, a three-dimensional HPLC (3D-HPLC) system has been designed and developed by investigating the separation of the target analytes from unknown substances observed in the real target matrices. LA and 3HB were pre-column derivatized with 4-nitro-7-piperazino-2,1,3-benzoxadiazole for the sensitive fluorescence detection and introduced into the 3D-HPLC system composed of reversed-phase, mixed-mode and enantioselective separations. The present method was validated by calibration curves, precision and accuracy using standard solutions and human samples, and sufficient values were obtained. Using the method, the levels of d-LA, l-LA, d-3Hb and l-3HB were determined, and their concentrations were 9.9, 1004.2, 79.7 and 2.1 μM in the human plasma and 16.0, 86.6, 8.7 and 4.8 μM in the human urine, respectively. The present 3D-HPLC system could selectively determine trace amounts of the target hydroxy acid enantiomers without disturbance of the intrinsic interfering substances in complicated matrices and the applications to various disease samples are expected.

Disrupted Mitochondrial and Metabolic Plasticity Underlie Comorbidity between Age-Related and Degenerative Disorders as Parkinson Disease and Type 2 Diabetes Mellitus

Idiopathic Parkinson’s disease (iPD) and type 2 diabetes mellitus (T2DM) are chronic, multisystemic, and degenerative diseases associated with aging, with eventual epidemiological co-morbidity and overlap in molecular basis. This study aims to explore if metabolic and mitochondrial alterations underlie the previously reported epidemiologic and clinical co-morbidity from a molecular level. To evaluate the adaptation of iPD to a simulated pre-diabetogenic state, we exposed primary cultured fibroblasts from iPD patients and controls to standard (5 mM) and high (25 mM) glucose concentrations to further characterize metabolic and mitochondrial resilience. iPD fibroblasts showed increased organic and amino acid levels related to mitochondrial metabolism with respect to controls, and these differences were enhanced in high glucose conditions (citric, suberic, and sebacic acids levels increased, as well as alanine, glutamate, aspartate, arginine, and ornithine amino acids; p-values between 0.001 and 0.05). The accumulation of metabolites in iPD fibroblasts was associated with (and probably due to) the concomitant mitochondrial dysfunction observed at enzymatic, oxidative, respiratory, and morphologic level. Metabolic and mitochondrial plasticity of controls was not observed in iPD fibroblasts, which were unable to adapt to different glucose conditions. Impaired metabolism and mitochondrial activity in iPD may limit energy supply for cell survival. Moreover, reduced capacity to adapt to disrupted glucose balance characteristic of T2DM may underlay the co-morbidity between both diseases. Conclusions: Fibroblasts from iPD patients showed mitochondrial impairment, resulting in the accumulation of organic and amino acids related to mitochondrial metabolism, especially when exposed to high glucose. Mitochondrial and metabolic defects down warding cell plasticity to adapt to changing glucose bioavailability may explain the comorbidity between iPD and T2DM.

Uncovering a superfamily of nickel-dependent hydroxyacid racemases and epimerases

Isomerization reactions are fundamental in biology. Lactate racemase, which isomerizes L- and D-lactate, is composed of the LarA protein and a nickel-containing cofactor, the nickel-pincer nucleotide (NPN). In this study, we show that LarA is part of a superfamily containing many different enzymes. We overexpressed and purified 13 lactate racemase homologs, incorporated the NPN cofactor, and assayed the isomerization of different substrates guided by gene context analysis. We discovered two malate racemases, one phenyllactate racemase, one α-hydroxyglutarate racemase, two D-gluconate 2-epimerases, and one short-chain aliphatic α-hydroxyacid racemase among the tested enzymes. We solved the structure of a malate racemase apoprotein and used it, along with the previously described structures of lactate racemase holoprotein and D-gluconate epimerase apoprotein, to identify key residues involved in substrate binding. This study demonstrates that the NPN cofactor is used by a diverse superfamily of α-hydroxyacid racemases and epimerases, widely expanding the scope of NPN-dependent enzymes.

Quantitative Evaluation of D-Lactate Pathophysiology: New Insights into the Mechanisms Involved and the Many Areas in Need of Further Investigation

In contrast to L-lactate, D-lactate is produced in minimal quantities by human cells, and the plasma D-lactate concentration normally is maintained at a concentration of only about 0.01 mM. However, in short bowel syndrome, colonic bacterial production of D-lactate may lead to plasma concentrations >3mM with accompanying acidosis and neurological symptoms - a syndrome known as D-lactic acidosis. Minor increases in plasma D-lactate have been observed in various gastrointestinal conditions such as ischemia, appendicitis and Crohn's disease, a finding touted to have diagnostic utility. The novel aspect of this review paper is the application of numerical values to the processes involved in D-lactate homeostasis that previously have been described only in qualitative terms. This approach provides a number of new insights into normal and disordered production, catabolism and excretion of D-lactate, and identifies multiple gaps in our understanding of D-lactate physiology that should be amenable to relatively simple investigative study.

Safety Assessment of a Nham Starter Culture Lactobacillus plantarum BCC9546 via Whole-genome Analysis

The safety of microbial cultures utilized for consumption is vital for public health and should be thoroughly assessed. Although general aspects on the safety assessment of microbial cultures have been suggested, no methodological detail nor procedural guideline have been published. Herein, we propose a detailed protocol on microbial strain safety assessment via whole-genome sequence analysis. A starter culture employed in traditional fermented pork production, nham, namely Lactobacillus plantarum BCC9546, was used as an example. The strain’s whole-genome was sequenced through several next-generation sequencing techniques. Incomplete plasmid information from the PacBio sequencing platform and shorter chromosome size from the hybrid Oxford Nanopore-Illumina platform were noted. The methods for 1) unambiguous species identification using 16S rRNA gene and average nucleotide identity, 2) determination of virulence factors and undesirable genes, 3) determination of antimicrobial resistance properties and their possibility of transfer, and 4) determination of antimicrobial drug production capability of the strain were provided in detail. Applicability of the search tools and limitations of databases were discussed. Finally, a procedural guideline for the safety assessment of microbial strains via whole-genome analysis was proposed.

D-Lactic Acid as a Metabolite: Toxicology, Diagnosis, and Detection

Two enantiomers of lactic acid exist. While L-lactic acid is a common compound of human metabolism, D-lactic acid is produced by some strains of microorganism or by some less relevant metabolic pathways. While L-lactic acid is an endogenous compound, D-lactic acid is a harmful enantiomer. Exposure to D-lactic acid can happen by various ways including contaminated food and beverages and by microbiota during some pathological states like short bowel syndrome. The exposure to D-lactic acid cannot be diagnosed because the common analytical methods are not suitable for distinguishing between the two enantiomers. In this review, pathways for D-lactic acid, pathological processes, and diagnostical and analytical methods are introduced followed by figures and tables. The current literature is summarized and discussed.

Albuterol-Induced Type B Lactic Acidosis: Not an Uncommon Finding

Lactic acidosis (LA) is usually a medical emergency diagnosed by laboratory evaluation in emergency rooms (ERs) and hospital settings in critically ill patients. LA is classified into two major types based on pathophysiology; type A results from tissue hypoxia and/or hypoperfusion and type B results from deranged metabolic activity in the cells in the absence of hypoxia/hypoperfusion. Prompt evaluation and treatment are essential to prevent morbidity and mortality, especially in patients with type A LA. Most cases of LA are due to type A (hypoperfusion/hypoxia). However, with increased testing of lactic acid levels in ERs and hospitals, we are encountering a few cases of type B LA as well. Diagnosing the exact type is crucial because of differences in management. We here describe a patient with albuterol-induced type B LA, which resolved after discontinuing the albuterol breathing treatments.

Challenges Associated with Byproducts Valorization-Comparison Study of Safety Parameters of Ultrasonicated and Fermented Plant-Based Byproducts

In order to promote the efficient use of byproducts from the production of plant-based beverages, which still contain a large amount of nutritional and functional compounds, microbiological and chemical safety characteristics should be evaluated and, if needed, improved. Many challenges are associated with byproducts valorization, and the most important ones, which should be taken into account at the further steps of valorization, are biological and chemical safety. For safety improving, several technological treatments (biological, physical etc.) can be used. In this study, the influence of low-frequency ultrasonication (US) and fermentation with Lactobacillus casei LUHS210 strain, as physical and biotechnological treatments, on the safety characteristics of the byproducts (BYs) from the processing of rice, soy, almond, coconut, and oat drinks was compared. Ultrasonication, as well as fermentation, effectively improved the microbiological safety of BYs. Ultrasonication and fermentation reduced the concentration of deoxynivalenol, on average, by 24% only in soy BYs. After fermentation, 15-acetyldeoxynivalenol was formed in all samples (<12 µg kg⁻¹), except for soy BYs. The lowest total biogenic amines content was found in fermented rice BYs and ultrasonicated coconut BYs. When comparing untreated and fermented BYs, significant changes in macro- and micro-elements content were found. Ultrasonication at 37 kHz did not significantly influence the concentrations of macro- and micro-elements, while fermentation affected most of the essential micro-elements. Consequently, while ultrasonication and fermentation can enhance the safety of BYs, the specific effects must be taken into account on biogenic amines, mycotoxins, and micro and macro elements.

Probiotics in Autoimmune and Inflammatory Disorders

Probiotics have been used to ameliorate gastrointestinal symptoms since ancient times. Over the past 40 years, probiotics have been shown to impact the immune system, both in vivo and in vitro. This interaction is linked to gut microbes, their polysaccharide antigens, and key metabolites produced by these bacteria. At least four metabolic pathways have been implicated in mechanistic studies of probiotics, based on mechanistic studies in animal models. Microbial⁻immune system crosstalk has been linked to: short-chain fatty acid production and signaling, tryptophan metabolism and the activation of aryl hydrocarbon receptors, nucleoside signaling in the gut, and activation of the intestinal histamine-2 receptor. Several randomized controlled trials have now shown that microbial modification by probiotics may improve gastrointestinal symptoms and multiorgan inflammation in rheumatoid arthritis, ulcerative colitis, and multiple sclerosis. Future work will need to carefully assess safety issues, selection of optimal strains and combinations, and attempts to prolong the duration of colonization of beneficial microbes.