Designer probiotic Lactobacillus plantarum expressing oxalate decarboxylase developed using group II intron degrades intestinal oxalate in hyperoxaluric rats

Abstract

Increased intestinal absorption of oxalate causes hyperoxaluria, a major risk factor for kidney stone disease. Intestinal colonization of recombinant probiotic bacteria expressing oxalate-degrading gene (OxdC) is an effective therapeutic option for recurrent calcium oxalate (CaOx) stone disease. Therefore, we aimed to develop food-grade probiotic L. plantarum secreting OxdC using lactococcal group II intron, Ll.LtrB and evaluate its oxalate degradation ability in vivo. Male Wistar albino rats were divided into four groups. The rats of group I received normal rat chow and drinking water. Groups II, III and IV rats received 5% potassium oxalate containing diet for 28 days. Groups III and IV rats received L. plantarum and food-grade recombinant L. plantarum respectively from 15 to 28 days. Biochemical parameters and crystalluria were analysed in 24 h urine samples. At the end of experimental period, rats were sacrificed; intestine and kidneys were dissected out for colonization studies and histopathological analysis. Herein, we found that the administration of recombinant probiotics significantly reduced the urinary oxalate, calcium, urea, and creatinine levels in rats of group IV compared to group II. Furthermore, colonization studies indicated that recombinant probiotics have gastrointestinal transit and intestinal colonization ability similar to that of wild-type bacteria. In addition, gene expression studies revealed down-regulation of OPN and KIM-1 among group IV rats. Histopathological analysis showed less evidence of nephrocalcinosis in group IV rats. In conclusion, the study demonstrates that food-grade L. plantarum secreting OxdC is capable of degrading intestinal oxalate and thereby prevent CaOx stone formation in experimental rats.

Oxalate decarboxylase uses electron hole hopping for catalysis

“…Understanding the expression, gene regulation, structural organization, and catalytic mechanism of OxDC and related oxalate-degrading enzymes is expected to advance efforts to enhance fungal resistance in crop plants and to lower their oxalate concentration ( 30 , 31 ). Other potential applications are being explored in the areas of oxalate scale remediation ( 32 , 33 ), novel therapeutics for hyperoxaluria and kidney stones ( 34 , 35 ), and bioengineered probiotic gut bacteria ( 36 , 37 ). Efforts have also been made to modify the protein to improve its catalytic activity at normal pH ( 38 ).…”

Lactiplantibacillus plantarum Reduced Renal Calcium Oxalate Stones by Regulating Arginine Metabolism in Gut Microbiota

“…However, this study did not explore the underlying mechanisms. Later, some studies found that L. plantarum recombined with the oxalate decarboxylase gene could also reduce urinary levels (Sasikumar et al, 2014;Paul et al, 2018). However, these artificial bacteria may not be safe for humans.…”

Intestinal micro biota and its role in the pathogenesis of secondary hyperoxaluria in children

“…Было показано, что в группе крыс, которым вводились данные бактерии, отмечалось значительное снижение мочевой экскреции оксалатов, а также уровня креатинина и мочевой кислоты в сыворотке крови [39]. Сходные данные по способности L. plantarum разлагать оксалаты в кишечнике были получены и в других экспериментальных исследованиях [40][41][42].…”