Oxalate balance in fat sand rats feeding on high and low calcium diets

Palgi, Niv; Ronen, Zeev; Pinshow, Berry

doi:10.1007/s00360-008-0252-1

Cited by 13 publications

(14 citation statements)

References 21 publications

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“…Our results reveal that the transplant of fecal microbial communities increased total oxalate degradation by more than threefold with a corresponding decrease in urinary oxalate excretion by 48 %. Our results are on par with other transplant studies involving O. formigenes , a species that requires oxalate as a carbon and energy source, which have yielded a reduction in urinary oxalate of 49–70% [36, 37]. …”

Section: Discussionsupporting

confidence: 81%

“…The loss of the probiotic oxalate-degrading bacteria after the removal of dietary oxalate is in contrast to other mammals, such as fat sand rats ( Psammomys obesus ), sheep, and some humans, that harbor oxalate-degrading bacteria natively. In these mammals, the oxalate-degrading bacterial populations are maintained across generations, even when oxalate is removed from the diet [37–39]. …”

Section: Introductionmentioning

confidence: 99%

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Microbial Community Transplant Results in Increased and Long-Term Oxalate Degradation

et al. 2016

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Gut microbes are essential for the degradation of dietary oxalate, and this function may play a role in decreasing the incidence of kidney stones. However, many oxalate-degrading bacteria are susceptible to antibiotics and the use of oxalate-degrading probiotics has only led to an ephemeral reduction in urinary oxalate. The objective of the current study was to determine the efficacy of using whole-community microbial transplants from a wild mammalian herbivore, Neotoma albigula, to increase oxalate degradation over the long term in the laboratory rat, Rattus norvegicus. We quantified the change in total oxalate degradation in lab rats immediately after microbial transplants and at 2- and 9-month intervals following microbial transplants. Additionally, we tracked the fecal microbiota of the lab rats, with and without microbial transplants, using high-throughput Illumina sequencing of a hyper-variable region of the 16S rRNA gene. Microbial transplants resulted in a significant increase in oxalate degradation, an effect that persisted 9 months after the initial transplants. Functional persistence was corroborated by the transfer, and persistence of a group of bacteria previously correlated with oxalate consumption in N. albigula, including an anaerobic bacterium from the genus Oxalobacter known for its ability to use oxalate as a sole carbon source. The results of this study indicate that whole-community microbial transplants are an effective means for the persistent colonization of oxalate-degrading bacteria in the mammalian gut.

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Section: Discussionsupporting

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Microbial Community Transplant Results in Increased and Long-Term Oxalate Degradation

et al. 2016

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“…This is in contrast to mammals that are natural hosts to oxalate-degrading bacteria, such as the animals in the current study, which maintain those populations and their associated functions across generations and respond to increasing dietary oxalate even after long periods of time without oxalate in the diet (38,48,49). The transient colonization of the oxalate-degrading bacteria following probiotic treatment suggests that these transplanted bacteria are unable to integrate successfully into a foreign community, implying that there are underlying mechanisms of support for these bacteria in their natural hosts.…”

Section: Discussionmentioning

confidence: 84%

Effect of Dietary Oxalate on the Gut Microbiota of the Mammalian Herbivore Neotoma albigula

Miller

Oakeson

Dale

et al. 2016

Appl Environ Microbiol

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Diet is one of the primary drivers that sculpts the form and function of the mammalian gut microbiota. However, the enormous taxonomic and metabolic diversity held within the gut microbiota makes it difficult to isolate specific diet-microbe interactions. The objective of the current study was to elucidate interactions between the gut microbiota of the mammalian herbivore Neotoma albigula and dietary oxalate, a plant secondary compound (PSC) degraded exclusively by the gut microbiota. We quantified oxalate degradation in N. albigula fed increasing amounts of oxalate over time and tracked the response of the fecal microbiota using high-throughput sequencing. The amount of oxalate degraded in vivo was linearly correlated with the amount of oxalate consumed. The addition of dietary oxalate was found to impact microbial species diversity by increasing the representation of certain taxa, some of which are known to be capable of degrading oxalate (e.g., Oxalobacter spp.). Furthermore, the relative abundances of 117 operational taxonomic units (OTU) exhibited a significant correlation with oxalate consumption. The results of this study indicate that dietary oxalate induces complex interactions within the gut microbiota that include an increase in the relative abundance of a community of bacteria that may contribute either directly or indirectly to oxalate degradation in mammalian herbivores. Mammals live in a complex and largely symbiotic relationship with their gut microbiota. This microbiota harbors 150 times more genes than the host and exhibits complex interactions with the host's diet (1-3). In mammalian herbivores, diverse intestinal bacteria ferment a diet high in recalcitrant cellulose and in turn synthesize nutrients from the diet in a form more amenable to absorption by the host (4). Furthermore, mammalian herbivores harbor greater microbial diversity in their gut than either omnivores or carnivores (1). Despite the progress of research into the interactions between the mammalian gut microbiota and diet, the isolation of specific diet-microbe interactions in such a complex system has proven to be difficult (5, 6).In addition to having a role in fermentation, microbes play an important role in the biotransformation of dietary toxins in mammalian herbivores (4, 7-10). For some toxins, such as oxalate or 3,4-dihydroxypyridine (DHP), a single species of bacteria is capable of biotransforming the toxin, and this function can be transferred to other mammals through microbial transplants (7,8,11,12). For other toxins, such as creosote resin, whole microbial community transplantation into other mammals can increase tolerance (10).Oxalate, a widely produced and ingested plant secondary compound (PSC), serves as an excellent model to study diet-microbe interactions (13). It is the simplest organic acid and is toxic to mammals (14-16). Oxalate can bind to free calcium ions in the blood and aggregate in the kidneys to form kidney stones (17). In fact, oxalate is a constituent in 80% of kidney stones in humans (17). Oxala...

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“…Under such conditions, it would be advantageous for O. formigenes to have the ability to facilitate solubilization of dietary crystalline oxalate. Previous rodent studies suggested that oxalatedegrading organisms degrade calcium oxalate crystals (63,64); however, the mechanism by which this occurs is not known. In this study, O. formigenes-monocolonized mice excreted significantly more urinary calcium and phosphate than did germfree mice, which might be due to degradation of calcium oxalate and calcium phosphate crystals by O. formigenes and subsequent intestinal absorption of free calcium and phosphate.…”

Section: Discussionmentioning

confidence: 89%

Response of Germfree Mice to Colonization by Oxalobacter formigenes and Altered Schaedler Flora

Ellis

Dowell

et al. 2016

Appl Environ Microbiol

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Colonization with Oxalobacter formigenes may reduce the risk of calcium oxalate kidney stone disease. To improve our limited understanding of host-O. formigenes and microbe-O. formigenes interactions, germfree mice and mice with altered Schaedler flora (ASF) were colonized with O. formigenes. Germfree mice were stably colonized with O. formigenes, which suggests that O. formigenes does not require other organisms to sustain its survival. Examination of intestinal material indicated no viable O. formigenes in the small intestine and ϳ4 ؋ 10 6 CFU O. formigenes per 100 mg contents in the cecum and proximal colon, with ϳ0.02% of total cecal O. formigenes cells being tightly associated with the mucosa. O. formigenes did not alter the overall microbial composition of ASF, and ASF did not affect the capacity of O. formigenes to degrade dietary oxalate in the cecum. Twentyfour-hour collections of urine and feces in metabolic cages in semirigid isolators demonstrated that the introduction of ASF into germfree mice significantly reduced urinary oxalate excretion. These experiments also showed that O. formigenes-monocolonized mice excreted significantly more urinary calcium than did germfree mice, which may be due to degradation of calcium oxalate crystals by O. formigenes and subsequent intestinal absorption of free calcium. In conclusion, the successful establishment of mouse models with defined flora and O. formigenes should improve our understanding of O. formigenes-host and O. formigenes-microbe interactions. These data support the use of O. formigenes as a probiotic that has limited impact on the composition of the resident microbiota but provides an efficient oxalate-degrading function. Oxalobacter formigenes is part of the bacterial flora in the large intestine of many humans and other mammalian species and is unique in that it is the only bacterium yet identified in the intestines of mammals that requires oxalate as both an energy source and a carbon source. Recent evidence suggests that a lack of colonization with this oxalate-degrading specialist is a risk factor for idiopathic recurrent calcium oxalate stone disease (1, 2). A review of worldwide data indicated that 38% to 77% of a normal population and only 17% of stone formers were colonized with O. formigenes (1). The ability to recolonize individuals lacking O. formigenes was previously addressed in a study in which two healthy adults not colonized with O. formigenes became colonized following the ingestion of cultured O. formigenes (3) and remained colonized for 9 months. However, studies in which O. formigenes was provided in either a lyophilized form in enteric coated capsules or as a frozen paste to patients suffering from primary hyperoxaluria resulted in only a minority of the patients remaining colonized posttreatment (4, 5). Therefore, although it seems quite possible that O. formigenes colonization of noncolonized stone formers may be an effective way to minimize the risk of recurrent calcium oxalate stone disease, a better understanding o...

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Oxalate balance in fat sand rats feeding on high and low calcium diets

Cited by 13 publications

References 21 publications

Microbial Community Transplant Results in Increased and Long-Term Oxalate Degradation

Microbial Community Transplant Results in Increased and Long-Term Oxalate Degradation

Effect of Dietary Oxalate on the Gut Microbiota of the Mammalian Herbivore Neotoma albigula

Response of Germfree Mice to Colonization by Oxalobacter formigenes and Altered Schaedler Flora

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