Lower gut microbiome diversity and higher abundance of proinflammatory genus Collinsella are associated with biopsy-proven nonalcoholic steatohepatitis.

There is increasing evidence for the role of gut microbial composition in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Nonalcoholic steatohepatitis (NASH) is the most serious form of NAFLD where inflammation causes liver damage that can progress to cirrhosis. We have characterized the gut microbiome composition in UK patients with biopsy-proven NASH (n = 65) and compared it to that in healthy controls (n = 76). We report a 7% lower Shannon alpha diversity in NASH patients without cirrhosis (n = 40) compared to controls (p = 2.7x 10-4) and a 14% drop in NASH patients with cirrhosis (n = 25, p = 5.0x 10-4). Beta diversity (Unweighted UniFrac distance) was also significantly reduced in both NASH (p = 5.6x 10-25) and NASH-cirrhosis (p = 8.1x 10-7) groups. The genus most strongly associated with NASH in this study was Collinsella (0.29% abundance in controls, 3.45% in NASH without cirrhosis (False Discovery Rate (FDR) p = .008), and 4.38% in NASH with cirrhosis (FDR p = .02)). This genus, which has been linked previously to obesity and atherosclerosis, was also positively correlated with fasting levels of triglycerides (p = .01) and total cholesterol (p = 1.2x 10-4) and negatively correlated with high-density lipoprotein cholesterol (p = 2.8x 10-6) suggesting that some of the pathways present in this microbial genus may influence lipid metabolism in the host. In patients, we also found decreased abundance of some of the Ruminococcaceae which are known to produce high levels of short-chain fatty acids which can lower inflammation. This may thus contribute to pathology associated with NASH.

Farm Stage, Bird Age, and Body Site Dominantly Affect the Quantity, Taxonomic Composition, and Dynamics of Respiratory and Gut Microbiota of Commercial Layer Chickens.

The digestive and respiratory tracts of chickens are colonized by bacteria that are believed to play important roles in the overall health and performance of the birds. Most of the current research on the commensal bacteria (microbiota) of chickens has focused on broilers and gut microbiota, and less attention has been given to layers and respiratory microbiota. This research bias has left significant gaps in our knowledge of the layer microbiome. This study was conducted to define the core microbiota colonizing the upper respiratory tract (URT) and lower intestinal tract (LIT) in commercial layers under field conditions. One hundred eighty-one chickens were sampled from a flock of >80,000 birds at nine times to collect samples for 16S rRNA gene-based bacterial metabarcoding. Generally, the body site and age/farm stage had very dominant effects on the quantity, taxonomic composition, and dynamics of core bacteria. Remarkably, ileal and URT microbiota were compositionally more related to each other than to that from the cecum. Unique taxa dominated in each body site yet some taxa overlapped between URT and LIT sites, demonstrating a common core. The overlapping bacteria also contained various levels of several genera with well-recognized avian pathogens. Our findings suggest that significant interaction exists between gut and respiratory microbiota, including potential pathogens, in all stages of the farm sequence. The baseline data generated in this study can be useful for the development of effective microbiome-based interventions to enhance production performance and to prevent and control disease in commercial chicken layers.IMPORTANCE The poultry industry is faced with numerous challenges associated with infectious diseases and suboptimal performance of flocks. As microbiome research continues to grow, it is becoming clear that poultry health and production performance are partly influenced by nonpathogenic symbionts that occupy different habitats within the bird. This study has defined the baseline composition and overlaps between respiratory and gut bacteria in healthy, optimally performing chicken layers across all stages of the commercial farm sequence. Consequently, the study has set the groundwork for the development of interventions that seek to enhance production performance and to prevent and control infectious diseases through the modulation of gut and respiratory bacteria.

Impact of Klebsiella pneumoniae in lower gastrointestinal tract diseases.

The 2016 Global Burden of Disease report by WHO revealed that diseases of the gastrointestinal tract (GIT) had one of the highest incidence rates worldwide. The plethora of factors that contribute to the development of GIT-related illnesses can be divided into genetic, environmental and lifestyle factors. Apart from that, the role that infectious agents play in the development of GIT diseases has piqued the interest of researchers worldwide. The human gut harbors approximately 1014 bacteria in it with increasing concentration toward the lower GIT. Among the various microbiota that colonize the human gut, Gram-negative bacteria have been most notoriously linked to GIT-related diseases such as inflammatory bowel disease (IBD) including Crohn's disease and ulcerative colitis and colorectal cancer (CRC). Some of the notable culprits that have been attributed to these diseases are Bacteroides fragilis, Fusobacterium nucleatum, Escherichia coli and Helicobacter pylori. However, studies in recent years are beginning to recognize a new player, Klebsiella pneumoniae (K. pneumoniae) in the causation and progression of GIT diseases. Once synonymous with infections and diseases of the upper respiratory tract, K. pneumoniae has now emerged as one of the pathogens commonly isolated from patients with GIT diseases. However, extensive studies attributing K. pneumoniae to GIT diseases, particularly that of CRC are scanty. Therefore, this review intends to shed light on the association of K. pneumoniae in gastrointestinal diseases such as Crohn's disease, ulcerative colitis as well as CRC.

Sexually transmitted infections of the lower gastrointestinal tract.

The World Health Organization estimates that there is greater than one million new cases of sexually transmitted infections (STIs) every day. In many countries, STIs are at an unprecedented high, including the USA, where nearly 20 million new cases were reported in 2016. Although morbidity associated with STIs is usually seen in the context of genitourinary disease, these pathogens may also affect the gastrointestinal tract and cause anal pain, abdominal pain, or diarrhea. It is important to recognize patterns of injury associated with these pathogens, especially those that may mimic other gastrointestinal diseases, such as idiopathic inflammatory bowel disease (IBD). This review focuses upon STIs of the lower gastrointestinal tract, organized by the most common site of involvement: the anus, rectum, and colon.

Distribution of Chlamydia Trachomatis Genotypes in Infective Diseases of the Female Lower Genital Tract.

The purpose of this study was to investigate the distribution of Chlamydia trachomatis (CT) genotypes in infective diseases of the female lower genital tract, especially in cervical diseases. This study included 128 CT-positive women. DNA was extracted from cervical swabs. Omp1 gene PCR-RFLP and sequencing were used to confirm the subtypes of CT. The association of subtypes with age, clinical symptoms, cervical cytology, and biopsy results was further analyzed. Omp1 gene PCR-RFLP and sequencing showed that the order of prevalent CT genotypes in the female lower genital tract was D (n=38, 29.69%), followed by E (n=28, 21.88%), G (n=21, 16.41%), and F (n=16,12.50%). Genotypes J, H, and K were comparatively rare. Genotype I was not identified in our samples. Further analysis showed that patients with genotype G were more frequently co-infected with other bacteria. Genotype G was also associated with mucopurulent cervicitis (MPC) and cervical intraepithelial neoplasia (CIN). Patients with genotype E were commonly co-infected with HR-HPV. Although genotype D was the most prevalent, it was a relatively low-risk type. These results provide information on distribution of CT genotypes in infective diseases of the female lower genital tract, which is instrumental to developing a vaccine for CT.

Fatty acid composition and phospholipid types used in infant formulas modifies the establishment of human gut bacteria in germ-free mice.

Human milk fat contains high concentrations of medium-chained fatty acids (MCFA) and triacylglycerols emulsified by a sphingomyelin-rich phospholipid membrane (milk phospholipids, MPL). Infant formula comprises mainly long-chained fatty acids (LCFA) emulsified with dairy proteins and soy lecithin (SL) lacking sphingomyelin. Sphingomyelin content and saturation level of phospholipids affect the gut lipase activity, which alters the concentrations of lipid hydrolysis products in ileum and colon, and hereby putatively affects the competitive advantage of specific gut bacteria. Thus, differences in phospholipid and FA composition may modulate the establishment of the gut microbiota. We investigated effects of fatty acid (FA) composition and emulsification (MPL vs SL) ingested during establishment of human gut microbiota in germ-free mice, and found that cecal microbiotas from mice given MCFA-rich emulsions were characterized by high relative abundances of Bacteroidaceae and Desulfovibrionaceae, while LCFA-rich emulsions caused higher abundances of Enterobacteriaceae, Erysipelotrichaceae, Coriobacteriaceae and Enterococcaceae. Consumption of SL-emulsified lipids skewed the community towards more Enterococcaceae and Enterobacteriaceae, while MPL increased Bacteroidaceae, Desulfovibrionaceae, Rikkenellaceae and Porphyromonadaceae. Intake of SL increased cecal concentrations of iso-valeric and iso-butyric acids. This suggests that fat-type and emulsifiers applied in infant formula may have distinct effects on the establishment of the gut microbiota in formula-fed infants.

Upper Versus Lower Gastrointestinal Delivery for Transplantation of Fecal Microbiota in Recurrent or Refractory Clostridium difficile Infection: A Collaborative Analysis of Individual Patient Data From 14 Studies.

GOALS: The aim of this study was to compare upper gastrointestinal (UGI) versus lower gastrointestinal (LGI) delivery routes of fecal microbiota transplantation (FMT) for refractory or recurrent/relapsing Clostridium difficile infection (CDI). BACKGROUND: FMT has been proven to be a safe and highly effective therapeutic option for CDI. Delivery, however, could be via the UGI or LGI routes, and it is unclear as to which route provides better clinical outcome. STUDY: A systematic search for studies that reported the use of FMT for CDI treatment was conducted. Individual patient data that included demographic (age and sex) and clinical (route of FMT delivery, CDI outcome after FMT, and follow-up time) information were obtained. Kaplan-Meier cumulative hazard curves and Cox proportional hazard models were used to assess clinical failure after FMT by the route of delivery. RESULTS: Data from 305 patients treated with FMT (208 via LGI route and 97 via UGI route) for CDI were analyzed. At 30 and 90 days, the risk of clinical failure was 5.6% and 17.9% in the UGI group compared with 4.9% and 8.5% in the LGI delivery route group, respectively. A time-varying analysis suggested a 3-fold increase in hazard of clinical failure for UGI delivery (hazard ratio, 3.43; 95% confidence interval, 1.32-8.93) in the period after 30 days. CONCLUSIONS: FMT delivered via the LGI seems to be the most effective route for the prevention of recurrence/relapse of CDI. A randomized controlled trial is necessary to confirm whether FMT delivered via the LGI is indeed superior to that delivered via the UGI route.

Exploring the effects of galacto-oligosaccharides on the gut microbiota of healthy adults receiving amoxicillin treatment.

In the present double-blind, randomised, parallel intervention study, the effects of the intake of galacto-oligosaccharides (GOS) on the gut microbiota of twelve healthy adult subjects (aged 18-45 years with a normal BMI (18-25 kg/m²)) receiving amoxicillin (AMX) treatment were determined. All the subjects were treated with AMX (375 mg; three times per d) for 5 d and given either GOS (n 6) or placebo (maltodextrin, n 6) (2·5 g; three times per d) during and 7 d after AMX treatment. Faecal samples were collected twice before starting the treatment and on days 2, 5, 8, 12, 19 and 26. Due to AMX treatment, a decrease in the abundance of Bifidobacterium spp., an overgrowth of Enterobacteriaceae, and a disruption of the metabolic activity of the microbiota (increase in succinate, monosaccharide and oligosaccharide levels in the faecal samples) were observed in both groups (P< 0·05). Positive effects of GOS intake were observed on the levels of bifidobacteria, although not found to be significant. Data revealed that the levels of bifidobacteria were higher upon GOS intake than upon placebo intake, especially after AMX treatment. The activity of bifidobacteria and subsequent cross-feeding activity of the microbiota upon GOS intake compared with those upon placebo intake were reflected by the significant increase in butyrate levels (P< 0·05) in the faecal samples after AMX treatment. Despite the small number of subjects, our findings confirm previous results obtained in vitro, namely that GOS intake supports the recovery of the beneficial bifidobacteria and, indirectly, the production of butyrate after AMX treatment.

Effects of iron supplementation on dominant bacterial groups in the gut, faecal SCFA and gut inflammation: a randomised, placebo-controlled intervention trial in South African children.

Fe supplementation is a common strategy to correct Fe-deficiency anaemia in children; however, it may modify the gut microbiota and increase the risk for enteropathogenic infection. In the present study, we studied the impact of Fe supplementation on the abundance of dominant bacterial groups in the gut, faecal SCFA concentration and gut inflammation in children living in rural South Africa. In a randomised, placebo-controlled intervention trial of 38 weeks, 6- to 11-year-old children with Fe deficiency received orally either tablets containing 50 mg Fe as FeSO4 (n 22) for 4 d/week or identical placebo (n 27). In addition, Fe-sufficient children (n 24) were included as a non-treated reference group. Faecal samples were analysed at baseline and at 2, 12 and 38 weeks to determine the effects of Fe supplementation on ten bacterial groups in the gut (quantitative PCR), faecal SCFA concentration (HPLC) and gut inflammation (faecal calprotectin concentration). At baseline, concentrations of bacterial groups in the gut, faecal SCFA and faecal calprotectin did not differ between Fe-deficient and Fe-sufficient children. Fe supplementation significantly improved Fe status in Fe-deficient children and did not significantly increase faecal calprotectin concentration. Moreover, no significant effect of Fe treatment or time × treatment interaction on the concentrations of bacterial groups in the gut or faecal SCFA was observed compared with the placebo treatment. Also, there were no significant differences observed in the concentrations of any of the bacterial target groups or faecal SCFA at 2, 12 or 38 weeks between the three groups of children when correcting for baseline values. The present study suggests that in African children with a low enteropathogen burden, Fe status and dietary Fe supplementation did not significantly affect the dominant bacterial groups in the gut, faecal SCFA concentration or gut inflammation.

In vitro activity on human gut bacteria of murta leaf extracts (Ugni molinae turcz.), a native plant from Southern Chile.

Despite the fact that murta infusions have been used to treat gut/urinary infections by native Chileans for centuries, the mechanisms promoting such effects still remain unclear. As a first attempt to unravel these mechanisms, human fecal samples were incubated in a medium containing water extract of murta leaves (ML) and the growth of different bacterial groups was evaluated. Control incubations were made in media containing fructooligosaccharides (FOS) and glucose as a carbon source. Phenolic compounds in the ML extract, likely promoters of bioactivity, were identified by HPLC-DAD-MS(n) . Concentrations (log10 CFU/mL) of bifidobacteria and lactobacilli in media containing the extract and FOS were 7.33 ± 0.05/4.95 ± 0.20 and 6.44 ± 0.22/6.05 ± 0.06, respectively. Clostridia, anaerobes and Enterobacteriaceae grew to a similar extent in media containing murta extract and FOS. In vitro tests (disk diffusion) showed that Gram-positive (Bacillus and Paenibacillaceae) and Gram-negative (Enterobacteriaceae) bacteria isolated from fecal samples were sensitive to both water and 50/50 ethanol/water extracts of ML (28.4 µg gallic acid equivalents). At this concentration, the antimicrobial activity of ML extracts was significantly (P < 0.05) lower than that of penicillin (10 U), whereas the difference between activity of ML extracts and gentamicine (10 µg) was no significant (P > 0.05). No evidence of dependency between the antimicrobial activity of ML extracts and the enzymatic capability of the sensitive strains was found.

Effect of purified ß-glucans derived from Laminaria digitata, Laminaria hyperborea and Saccharomyces cerevisiae on piglet performance, selected bacterial populations, volatile fatty acids and pro-inflammatory cytokines in the gastrointestinal tract of pigs.

ß-Glucans have been identified as natural biomolecules with immunomodulatory activity. The first objective of the present study was to compare the effects of purified ß-glucans derived from Laminaria digitata, L. hyperborea and Saccharomyces cerevisiae on piglet performance, selected bacterial populations and intestinal volatile fatty acid (VFA) production. The second aim was to compare the gene expression profiles of the markers of pro- and anti-inflammation in both unchallenged and lipopolysaccharide (LPS)-challenged ileal and colonic tissues. ß-Glucans were included at 250 mg/kg in the diets. The ß-glucans derived from L. hyperborea, L. digitata and S. cerevisiae all reduced the Enterobacteriaceae population (P<0·05) without influencing the lactobacilli and bifidobacteria populations (P>0·05) in the ileum and colon. There was a significant interaction between gastrointestinal region and ß-glucan source in the expression of cytokine markers, IL-1α (<0·001), IL-10 (P<0·05), TNF-α (P<0·05) and IL-17A (P<0·001). ß-Glucans did not stimulate any pro- or anti-inflammatory cytokine markers in the ileal epithelial cells. In contrast, the expression of a panel of pro- and anti-inflammatory cytokines (IL-1α, IL-10, TNF-α and IL-17A) was down-regulated in the colon following exposure to ß-glucans from all the three sources. However, the data suggest that the soluble ß-glucans derived from L. digitata may be acting via a different mechanism from the insoluble ß-glucans derived from L. hyperborea and S. cerevisiae, as the VFA profile was different in the L. digitata-treated animals. There was an increase in IL-8 gene expression (P<0·05) in the gastrointestinal tract from the animals exposed to L. digitata following an LPS ex vivo challenge that was not evident in the other two treatment groups. In conclusion, ß-glucans from both seaweed and yeast sources reduce Enterobacteriaceae counts and pro-inflammatory markers in the colon, though the mechanisms of action may be different between the soluble and insoluble fibre sources.

The gut microbiota and human health with an emphasis on the use of microencapsulated bacterial cells.

The gut microbiota plays a crucial role in maintaining health. Alterations of the gut bacterial population have been associated with a number of diseases. Past and recent studies suggest that one can positively modify the contents of the gut microbiota by introducing prebiotics, probiotics, synbiotics, and other therapeutics. This paper focuses on probiotic modulation of the gut microbiota by their delivery to the lower gastrointestinal tract (GIT). There are numerous obstacles to overcome before microorganisms can be utilized as therapeutics. One important limitation is the delivery of viable cells to the lower GIT without a significant loss of cell viability and metabolic features through the harsh conditions of the upper GIT. Microencapsulation has been shown to overcome this, with various types of microcapsules available for resolving this limitation. This paper discusses the gut microbiota and its role in disease, with a focus on microencapsulated probiotics and their potentials and limitations.

Helicobacter hepaticus infection in mice: models for understanding lower bowel inflammation and cancer.

Pioneering work in the 1990s first linked a novel microaerobic bacterium, Helicobacter hepaticus, with chronic active hepatitis and inflammatory bowel disease in several murine models. Targeted H. hepaticus infection experiments subsequently demonstrated its ability to induce colitis, colorectal cancer, and extraintestinal diseases in a number of mouse strains with defects in immune function and/or regulation. H. hepaticus is now widely utilized as a model system to dissect how intestinal microbiota interact with the host to produce both inflammatory and tolerogenic responses. This model has been used to make important advances in understanding factors that regulate both acquired and innate immune response within the intestine. Further, it has been an effective tool to help define the function of regulatory T cells, including their ability to directly inhibit the innate inflammatory response to gut microbiota. The complete genomic sequence of H. hepaticus has advanced the identification of several virulence factors and aided in the elucidation of H. hepaticus pathogenesis. Delineating targets of H. hepaticus virulence factors could facilitate novel approaches to treating microbially induced lower bowel inflammatory diseases.

Statin therapy and decreased incidence of positive Candida cultures among patients with type 2 diabetes mellitus undergoing gastrointestinal surgery.

OBJECTIVE: To assess whether statin therapy decreases the incidence of cultures positive for Candida species among high-risk hospitalized patients with type 2 diabetes mellitus (DM). PATIENTS AND METHODS: We performed a retrospective cohort study analyzing the records of all patients with type 2 DM who were admitted to Massachusetts General Hospital for lower gastrointestinal tract surgery between January 1, 2001, and May 1, 2008. We defined statin exposure as the filling of at least 1 prescription of statins during the 6 months before hospitalization or during the current hospital stay. The primary outcome was a culture positive for Candida species during hospitalization. Clinical information on a wide range of covariates was collected. Logistic regression analysis was used to adjust for possible confounders. RESULTS: Of the 1019 patients who were eligible for the study, 493 (48%) were receiving statins. A total of 139 patients (14%) had at least 1 culture positive for Candida species during hospitalization. An adjusted multivariate model based on a backward stepwise elimination procedure showed that statin therapy significantly decreased the incidence of cultures positive for Candida species (odds ratio, 0.60; 95% confidence interval [CI], 0.38-0.96; P=.03) with a statistically significant prolonged time to event compared with no statin therapy (adjusted hazard ratio, 0.62; 95% CI, 0.44-0.88; P=.01). The benefit of statins was more prominent in patients with type 2 DM who had greater comorbidities (Charlson Comorbidity Index ≥2) (adjusted odds ratio, 0.47; 95% CI, 0.27-0.79; P=.01). CONCLUSION: Among patients with type 2 DM who underwent gastrointestinal surgery, use of statins correlated with a decreased incidence of cultures positive for Candida species.

Lower gastrointestinal functions.

The human colon serves to absorb water and electrolytes, store intraluminal contents until elimination is socially convenient, and salvage nutrients by bacterial metabolism of carbohydrates that have not been absorbed in the small intestine. The anorectum is responsible for fecal continence and defecation. This article is a broad perspective of the current status and a personal perspective of future challenges in understanding lower gastrointestinal functions in health and disease in humans.

Efficacy of bacteriophage therapy against gut-derived sepsis caused by Pseudomonas aeruginosa in mice.

We evaluated the efficacy of bacteriophage (phage) therapy by using a murine model of gut-derived sepsis caused by Pseudomonas aeruginosa that closely resembles the clinical pathophysiology of septicemia in humans. Oral administration of a newly isolated lytic phage strain (KPP10) significantly protected mice against mortality (survival rates, 66.7% for the phage-treated group versus 0% for the saline-treated control group; P<0.01). Mice treated with phage also had lower numbers of viable P. aeruginosa cells in their blood, liver, and spleen. The levels of inflammatory cytokines (tumor necrosis factor alpha TNF-alpha, interleukin-1beta [IL-1beta], and IL-6) in blood and liver were significantly lower in phage-treated mice than in phage-untreated mice. The number of viable P. aeruginosa cells in fecal matter in the gastrointestinal tract was significantly lower in phage-treated mice than in the saline-treated control mice. We also studied the efficacy of phage treatment for intraperitoneal infection caused by P. aeruginosa and found that phage treatment significantly improved the survival of mice, but only under limited experimental conditions. In conclusion, our findings suggest that oral administration of phage may be effective against gut-derived sepsis caused by P. aeruginosa.

Gastrointestinal luminal tuberculosis: establishing the diagnosis.

BACKGROUND AND AIM: To study the profile of gastrointestinal luminal tuberculosis (GITB) patients who have been treated on a confirmed and a presumptive diagnosis. METHODS: A total of 260 patients who had an initial diagnosis of GITB were included in this retrospective analysis. Clinical, radiologic, endoscopic, histopathologic and microbiologic features of these patients were studied in detail. RESULTS: GITB was confirmed in 66.5% patients (cGITB), while 29.5% had presumed GITB (pGITB). In 3.9% patients, Crohn's disease (CD) was misdiagnosed initially as GITB. There was no significant difference in the clinical and radiologic features except a higher incidence of a radiologically abnormal ileocecal region in cGITB patients. Endoscopic biopsies from ulcerated masses and ulcers had the highest yield of confirmation (100% and 68%, respectively) when subjected to histopathology, acid-fast bacilli smear and culture studies. Confirmed diagnosis was obtained in 100% of cases occurring in the upper gastrointestinal tract, 66% of cases in the ileocecal region/colon and 40% of cases that had small bowel involvement. In 21% of cases, extraluminal sites helped to confirm the diagnosis. As the presence of diarrhea, bleeding, fistulae, perianal disease and extraintestinal manifestations favored a diagnosis of CD, the presence of these features initially or on subsequent follow up helped to minimize the misdiagnosis of GITB. CONCLUSIONS: As a differential diagnosis, CD must be ruled out before starting treatment for GITB. In our study, an intense search for histologic and microbiologic proof of the presence of TB from luminal and extraluminal sites established the diagnosis in 66.5% of cases. Surgery for establishing the diagnosis should be reserved for complicated cases.

Intelligent polyelectrolytes and gels in oral drug delivery.

The present review concerns smart, or intelligent polymers for oral administration that change conformation in aqueous solutions in response to external stimuli such as pH or temperature. We concentrate on charged polymers and gels with polyelectrolyte properties. Because of the ionization at a certain pH or in response to changes in the ionic composition of the solution, a polyelectrolyte has better chances of displaying smart properties than a neutral polymer. When such smart polyelectrolyte is cross-linked by covalent or hydrogen bonding and/or physical aggregation or is entangled, it forms an environmentally sensitive gel capable of swelling and collapse in an aqueous medium. Varying pH, temperature, and microbial flora are found in the gastrointestinal tract, and thus pH- sensitive polymers and gels that can be degraded by specific enzymes and/or inhibit proteolytic enzymes can be tailored for the efficient site-specific therapy. Smart polymers wield a lot of promise in the targeted, site-specific administration where they can provide advantages in loading of sensitive drugs such as proteins and peptides, while releasing the drug at a specific pH or in response to the presence of certain microbial flora.