Comparative efficacy and safety of lactulose plus paraffin vs polyethylene glycol in functional constipation: a randomised clinical study

Engineering the substrate-binding pocket of Cellobiose 2-epimerase for enhancing lactulose biosynthesis

Cellobiose 2-epimerase (CE) converts lactose into lactulose and epilactose with high added value and prebiotic benefits. However, the low conversion of lactulose by CsCE limits its industrial application. Inspired by previous work introducing engineered disulfide bonds on the loop of CsCE, we performed saturation mutagenesis and high-throughput screening of all residues within 4 Å of the engineered disulfide bond. The best mutant, CsCE-S173C/F231C/L172S/I178V(M4), showed a 1.3-fold increase in isomerization activity over CsCE-S173C/F231C. Molecular dynamics simulations and binding pocket analysis revealed that mutations reshaped the shape and size of the substrate-binding pocket and increased non-covalent interactions of the protein with the ligand. Binding free energy calculations showed a higher binding affinity of M4 for lactose and lactulose. Therefore, we demonstrated that the catalytic characteristics of CE can be modulated by further manipulating the loop region near the pocket, which is important for improving the catalytic efficiency and promiscuity of the enzyme.

Comparative Efficacy and Safety of Lubiprostone and Osmotic Laxatives in Chronic Idiopathic Constipation: A Systematic Review and Network Meta-Analysis

OBJECTIVE

The objective of this study is to compare the efficacy and safety of lubiprostone (Lub) with osmotic laxatives in the treatment of chronic idiopathic constipation (CIC).

METHODS

A comprehensive literature search was conducted using PubMed, EMBASE, and the Cochrane Library in May 2024. Studies that met the inclusion criteria were manually searched by two independent reviewers. The efficacy was assessed by the proportion of patients with spontaneous bowel movements (SBMs) within 24 h after the first administration of the medication and SBMs in Weeks 1 and 4. Safety was evaluated based on adverse events including nausea, diarrhea, and abdominal distension. Optimal probability values and the surface under the cumulative ranking area (SUCRA) were also calculated for all interventions. Higher SUCRA values indicate better efficacy and safety of the intervention.

RESULTS

Following a thorough search and screening process, 25 articles were included. Among the selected trials, 8 compared Lub to placebo, 10 compared polyethylene glycol (PEG) to placebo, 4 compared lactulose (Lac) to placebo, and 3 compared PEG to Lac. The meta-analysis results indicated that Lub and osmotic laxatives were significantly more effective than placebo. According to the SUCRA results, the highest rank probabilities were for Lub in increasing the SBMs and reducing abdominal distension.

CONCLUSION

Lubiprostone is more effective than PEG and Lactulose for treating CIC, with comparable safety profiles. However, this conclusion requires further validation through large-scale, high-quality studies.

Analysis of the efficacy of lactulose combined with polyethylene glycol in the treatment of functional constipation

OBJECTIVES

This study focuses on analyzing the efficacy of lactulose oral solution combined with Macrogol 4000 Powder in the treatment of functional constipation (FC).

METHODS

A total of 125 FC patients were selected, with 60 cases in a control group, who were treated with lactulose oral solution alone, and 65 cases in a research group, who were treated with lactulose oral solution combined with Macrogol 4000 Powder. The two groups were analyzed and compared in terms of efficacy, symptom recovery, Bristol Stool Form Scale (BSFS) and Wexner Constipation Scale (WCS) scores, adverse effects, serum indices, and Patient Assessment of Constipation Quality of Life (PAC-QOL). Univariate and multivariate analyses were performed to identify risk factors affecting the efficacy.

RESULTS

The total response rate of treatment in the research group was higher than that in the control group, and the symptom recovery was significantly better in the research group. In addition, the research group showed markedly elevated BSFS scores and reduced WCS scores after treatment as compared to the control group. Furthermore, significantly better improvements in various serum indices were determined in the research group. There was no remarkable difference in the incidence of total adverse reactions between groups. Finally, the course of disease, hypertension, diabetes, hyperlipidemia, and therapeutic method were identified to be factors affecting treatment efficacy in patients with FC.

CONCLUSIONS

The efficacy therapeutic of lactulose oral solution combined with Macrogol 4000 Powder in the treatment of FC is promising.

Multiple Regulatory Mechanisms Synergistically Control the Soluble Expression of CsCE for Enhanced Enzymatic Productivity of Lactulose in E. coli

The limited expression of cellobiose 2-epimerase poses a significant constraint on the industrial enzymatic production of lactulose. Extensive modifications to the expression cassette offer a means to enhance the yield of recombinant proteins. In this study, an integrated strategy, combining individual and collaborative approaches, is proposed to fine-tune each stage of the CsCE overexpression program. This strategy involves the multidimensional integration of standardized genetic elements at various levels, including transcription, translation, folding, and three-dimensional structure. The volumetric activity of the final recombinant strain was markedly increased by 12-fold compared to the wild-type strain, reaching 2260.62 U/L. The protein expression in the newly developed high-yield recombinant strain exhibited a significant enhancement, with a higher proportion of soluble protein compared to that of inclusion bodies. Our findings offer insights into the multifaceted synergistic regulation of protein expression processes, holding promising implications for the production of heterologous recombinant proteins.

Lactulose vs Polyethylene Glycol for Bowel Preparation: A Single-Center, Prospective, Randomized Controlled Study Based on BMI

INTRODUCTION

Colonoscopy is currently considered as one of the principal techniques to diagnose the colorectal diseases. Admittedly, qualified bowel preparation before colonoscopy is a premise for high-quality examination. Lower quality bowel preparation might seriously impede visualization of the intestinal mucosa, resulting in missed and misdiagnosed intestinal lesions. Therefore, it is necessary to choose the appropriate oral laxative based on the guarantee of safety and efficacy.

METHODS

This prospective randomized controlled study was conducted to compare lactulose oral solution and polyethylene glycol (PEG) electrolyte powder for bowel preparation using the following indicators: Boston Bowel Preparation Scale, Bowel Bubble Score, detection rate of adenoma and lesion, patients' satisfaction, and adverse effects. Our study investigated the suitability of 2 bowel preparation reagents for patients with different body mass indices mainly based on body mass index (BMI).

RESULTS

In the lactulose group, there was a significant improvement in the quality of bowel preparation compared with those in the PEG group ( P < 0.05), especially in people with normal BMI and higher BMI. Compared with the PEG group, individuals in the lactulose group had a significantly higher adenoma detection rate (50% vs 33.5%, P < 0.05) and taste scores (8.82 vs 6.69, P < 0.05), as well as significantly fewer adverse reactions (6.5% vs 32.5%, P < 0.05).

DISCUSSION

Lactulose oral solution is superior to PEG in bowel preparation quality and taste, especially in normal BMI and higher BMI groups. It can be used clinically as a potential and promising bowel preparation agent in the future. Clinical Trial registration number: ChiCTR2100054318.

Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review

INTRODUCTION

Constipation is commonly treated with over-the-counter (OTC) products whose efficacy and safety remain unclear. We performed a systematic review of OTC therapies for chronic constipation and provide evidence-based recommendations.

METHODS

We searched PubMed and Embase for randomized controlled trials of ≥4-week duration that evaluated OTC preparations between 2004 and 2020. Studies were scored using the US Preventive Services Task Force criteria (0-5 scale) including randomization, blinding, and withdrawals. The strengths of evidence were adjudicated within each therapeutic category, and recommendations were graded (A, B, C, D, and I) based on the level of evidence (level I, good; II, fair; or III, poor).

RESULTS

Of 1,297 studies identified, 41 met the inclusion criteria. There was good evidence (grade A recommendation) for the use of the osmotic laxative polyethylene glycol (PEG) and the stimulant senna; moderate evidence (grade B) for psyllium, SupraFiber, magnesium salts, stimulants (bisacodyl and sodium picosulfate), fruit-based laxatives (kiwi, mango, prunes, and ficus), and yogurt with galacto-oligosaccharide/prunes/linseed oil; and insufficient evidence (grade I) for polydextrose, inulin, and fructo-oligosaccharide. Diarrhea, nausea, bloating, and abdominal pain were common adverse events, but no serious adverse events were reported.

DISCUSSION

The spectrum of OTC products has increased and quality of evidence has improved, but methodological issues including variability in study design, primary outcome measures, trial duration, and small sample sizes remain. We found good evidence to recommend polyethylene glycol or senna as first-line laxatives and moderate evidence supporting fiber supplements, fruits, stimulant laxatives, and magnesium-based products. For others, further validation with more rigorously designed studies is warranted.

Efficacy and Safety of Acupuncture at Tianshu (ST25) for Functional Constipation: Evidence from 10 Randomized Controlled Trials

OBJECTIVE

To evaluate the evidence for the efficacy and safety of acupuncture at Tianshu (ST25) for functional constipation (FC).

METHODS

We systematically searched seven databases to identify randomized controlled trials of acupuncture at ST25 alone or in combination with conventional therapy in the treatment of FC. Risk ratios (RRs) and mean differences (MDs) were calculated using RevMan 5.3 with 95% confidence interval (CI).

RESULTS

The study included ten trials with 1568 participants. Meta-analysis showed that the Cleveland Constipation Score (CCS) for deep needling was significantly lower than that for lactulose (deep needling with low-frequency dilatational wave: MD -0.58, 95% CI -0.94 to -0.22; deep needling with sparse wave: MD -3.67, 95% CI -6.40 to -0.94; deep needling with high-frequency dilatational wave: MD -3.42, 95% CI -5.03 to -1.81). Furthermore, CCS for shallow needling with high-frequency dilatational wave was lower than that for lactulose (MD -1.77, 95% CI -3.40 to -0.14). In addition, when deep needling was combined with high-frequency dilatational wave, the weekly frequency of spontaneous defecation (FSD) was significantly higher than that for lactulose (MD 1.57, 95% CI 0.93 to 2.21). Colonic Transit Time (CTT) scores were significantly higher when deep needling was combined with sparse wave (MD -14.36, 95% CI -18.31 to -10.41) or high-frequency dilatational wave (MD -11.53, 95% CI -19.25 to -3.81). The time of first defecation after treatment (TFD) of the shallow needling therapy was significantly longer than that of the lactulose (MD 13.67, 95% CI 5.66 to 21.67). The CCS 6 months after treatment (CCS6m) for deep needling was significantly lower than that for lactulose (MD -4.90, 95% CI -5.97 to -3.84). Moreover, the FSD 6 months after treatment (FSD6m) for shallow needling was significantly higher than that for lactulose (MD 0.49, 95% CI 0.02 to 0.97). The adverse event (AE) rate for lactulose was significantly higher than that achieved with the needling treatments, and this held true for both deep needling therapy (RR 0.41, 95% CI 0.23 to 0.72) and shallow needling therapy (RR 0.33, 95% CI 0.15 to 0.77).

CONCLUSIONS

The meta-analysis demonstrates that acupuncture at ST25 appears to be more effective than lactulose in the treatment of functional constipation. This was found to be especially true for deep needling with high-frequency dilatational wave, which had a greater impact on improving CCS, FSD, CTT, and CCS6m. Additionally, acupuncture at ST25 was shown to be safer than conventional treatment, with the rate of AE being significantly lower for both deep needling and shallow needling. The trial is registered with https://www.crd.york.ac.uk/prospero/(CRD42019141017)).