ИЗТОЧНИК : NCBI
"
Cross-talk between Akkermansia muciniphila and intestinal epithelium controls diet-induced obesity.
Everard A1, Belzer C, Geurts L, Ouwerkerk JP, Druart C, Bindels LB, Guiot Y, Derrien M, Muccioli GG, Delzenne NM, de Vos WM, Cani PD.
Author information
- 1Metabolism and Nutrition Research Group, Walloon Excellence in Life sciences and BIOtechnology (WELBIO), Louvain Drug Research Institute, Université catholique de Louvain, B-1200 Brussels, Belgium.
Abstract
Obesity
and type 2 diabetes are characterized by altered gut microbiota,
inflammation, and gut barrier disruption. Microbial composition and the
mechanisms of interaction with the host that affect gut barrier function
during obesity and type 2 diabetes have not been elucidated. We
recently isolated Akkermansia muciniphila, which is a mucin-degrading
bacterium that resides in the mucus layer. The presence of this
bacterium inversely correlates with body weight in rodents and humans.
However, the precise physiological roles played by this bacterium during
obesity and metabolic disorders are unknown. This study demonstrated
that the abundance of A. muciniphila decreased in obese and type 2
diabetic mice. We also observed that prebiotic feeding normalized A.
muciniphila abundance, which correlated with an improved metabolic
profile. In addition, we demonstrated that A. muciniphila treatment
reversed high-fat diet-induced metabolic disorders, including fat-mass
gain, metabolic endotoxemia, adipose tissue inflammation, and insulin
resistance. A. muciniphila administration increased the intestinal
levels of endocannabinoids that control inflammation, the gut barrier,
and gut peptide secretion. Finally, we demonstrated that all these
effects required viable A. muciniphila because treatment with
heat-killed cells did not improve the metabolic profile or the mucus
layer thickness. In summary, this study provides substantial insight
into the intricate mechanisms of bacterial (i.e., A. muciniphila)
regulation of the cross-talk between the host and gut microbiota. These
results also provide a rationale for the development of a treatment that
uses this human mucus colonizer for the prevention or treatment of
obesity and its associated metabolic disorders. "
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Още едно медицинско проучване по темата тук :
Recently, I’m interested in a gut bacterium – Akkermansia muciniphila. After reading all the papers on PubMed about it, I am going to wrap it up.
Akkermansia muciniphila (a species in the phylum Verrucomicriobia), first proposed in 2004 (1), is a mucin-degrading gut bacterium. It starts to colonize the GI tract in early life and within a year it reaches to a level close to that observed in adults (2). It’s abundant in the human intestine, accounting for approximately 1-3% of the total microbiota (3). It’s also abundant in other animals. It resides in mucus layer and grows on mucin as a sole carbon and nitrogen source (4).
By the way, what are mucins and what are the functions of the mucus layer? Here are the answers (4):
We know, the balance of the gut microbiota is critical for our health, but the balance is easily disturbed in our modern life. This of course affects Akkermansia muciniphila too. So what will cause Akkermansia muciniphila to decrease in the gut?
1. Obesity (5, 6, 7, 8). Obesity is associated with chronic low-grade inflammation. The mechanism goes like this: when Akkermansia muciniphila decreases, mucus layer becomes thinner and intestinal lining becomes weaker, leading to leaky gut, and then metabolic endotoxins enter the blood stream and cause chronic low-grade inflammation associated with obesity.
2. Type 2 diabetes (7, 9, 10). Why? Inflammation? The role of gut hormones (affected by gut microbiota) in glucose homeostasis? Bile acids (metabolized by gut microbiota) as signalling molecules involved in the regulation of biosynthetic and metabolic pathways in the gut and liver? Researchers are still exploring…
3. Inflammatory bowel diseases (IBD, both Crohn’s disease and ulcerative colitis) (11, 12, 13). The richness and diversity of gut microbiota decrease in IBD; Akkermansia is reduced many fold and even depleted.
4. Autism (14). Possible reasons: increased gut permeability or altered mucus turnover.
5. Acute appendicitis (15). Most cases of acute appendicitis are caused by local infection with Fusobacterium nucleatum/necrophorum. Main fecal microbiota such as Akkermansia muciniphila is inversely related to the severity of this disease.
6. Atopy (16). According to the study, “The intestinal microbiota of atopic children showed a significant depletion in members of the Clostridium cluster IV, Faecalibacterium prausnitzii, Akkermansia muciniphila and a corresponding increase of the relative abundance of Enterobacteriaceae,” which is pro-inflammatory.
7. Psoriatic arthritis and skin psoriasis (17). Patients with these problems have less diverse gut microbiota and a significant reduction in Akkermansia. The gut microbiota profile in patients with psoriatic arthritis is similar to that in patients with IBD and associated with changes in specific inflammatory proteins.
8. Nonalcoholic fatty liver disease (NAFLD) (18). There is an association between some gut microbiota and the gut-liver axis, but their mechanism of developing NAFLD is unknown. For Akkermansia muciniphila, it may due to its decrease causing a thinner mucus layer and leaky gut.
9. Old age (2).
As mentioned above, a decrease in Akkermansia muciniphila has an adverse effect on health. We need to have certain amount of Akkermansia muciniphila (1-3%) to keep the mucus layer in shape with respect to mucus production and thickness and to further maintain the integrity of the epithelial cells which lay underneath.
How can we increase Akkermansia muciniphila in the gut?
1. Gluten-free diet (19, 20). Dietary gluten can influence the composition of gut microbiota. When mice were fed gluten-free chows (GFC, see the figure below), their Akkermansia muciniphila increased; but adding gluten back reversed the effect. The two papers show that a gluten-free diet may reduce inflammation and the incidence of diabetes.
2. Prebiotics, such as arabinoxylan (a hemicellulose) or inulin (21) and xylooligosaccharides (XOS) (22). Prebiotics can increase the number of goblet cells (to secrete mucins) and mucus layer thickness, promoting the growth of Akekrmansia muciniphila.
3. Fasting (23, 24). A lack of food encourages the growth of Akkermansia muciniphila. Animals studies show that fasting increased Akkermansia muciniphila; however, total gut microbiota or overall diversity and short-chain fatty acids decreased.
4. Viable but not heat-killed Akkermansia muciniphila (oral administration) (5).
5. Medical treatment (This is not for everybody): metformin for type-2 diabetes (25), gastric bypass for obesity (26, 27), and some antibiotics (28) (I don’t get it. Because Akkermansia muciniphila has better survival skills?).
As for an increase or decrease in Akkermansia muciniphila, there are a couple of conflicting results of its studies:
Type 2 resistant starch (RS2), a dietary fiber from raw potato starch, green banana and high amylose corn: This study (29) shows that, mice fed RS2 (0, 18%, or 36%) had an increase in Akkermansia muciniphila. But when you look at its diagram, only a few mice fed 36% RS2 showed some Akkermansia muciniphila. Hmm, the researchers tossed out data. Thank Dr. Grace Liu from Animal Pharm for pointing this out to me. She has 6 or 7 human examples on her blog show Akkermansia muciniphila decreases 2-fold on RS2 on even low dosage of 10 g/day. This makes a lot of sense to me – they are human data and humans are not evolved to eat raw potato starch.
High-fat diet: Mice studies again. Akkermansia muciniphila grew well in the gut of mice fed a high-fat, fiber-free diet (30). Akkermansia muciniphila degrades mucin and can exist in the gut without any dietary fiber. It is perhaps not surprising that it increased. However, in another study (5), researchers observed a 46% thinner mucus layer and a 100-fold decrease of Ammermansia muciniphila in high-fat fed mice. More studies are needed to clarify these mixed results.
Akkermansia muciniphila has some promising hope for inflammatory and diet-related disorders. It may be one of the next generation of probiotics for our health.
(Courtesy of http://www.gezondheid.be)
В резюме : Akkermansia muciniphila ( в тип Verrucomicriobia) Тя започва да колонизира в стомашно-чревния тракт в началото на живота и в рамките на една година нормално трябва да достигне до ниво, близко до това при възрастните. Тя е широко разпространен в човешките черва, което представлява приблизително 1-3% от общото микрофлора. Тъй като по време на първата година от живота децата се ваксинират интензивно,което според много мед. доклади води до нарушаване на стомашно -чревната флора , не е възможно тази бактерия да достигне нужните нива в тялото. Именно в еднио от медицинските проучвания по горе е засегната темата за децата аутисти и нивата на тази бактерия в телата им. Глутенът пречи да се размножава въпросната бактерия и именно за това се препоръчва безглутенова диета при деца с аутизъм .
Нарушаването на нормалната стомашно-чревна флора и в частност -налаляване на нужното ниво на Akkermansia muciniphila бу могло да причини следните здравословни проблеми :
1. Затлъстяване
2. Диабет тип 2
3. Възпалителни заболявания на червата
4. Аутизъм ( Възможни причини: увеличена чревна пропускливост и качеството и количеството на слузтта .
5. остър апендицит
6. Атопия (Атопична кожа )
7. Псориатичен артрит и псориазис.
8. Чернодробно заболяване - не в следствие от употребата на алкохол .
9. Преждвременно остаряване ,влошаване качеството на живот
10.
Източник : http://www.biotanutrition.com/2015/01/17/akkermansia-muciniphila-a-biomarker-of-healthy-gut/
==========================================================
Ето тук медицински доклад на NCBI ,който обсъжда темата : Специфични пробиотици облекчат алергичен ринит по време на поленовия сезон . http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2710782/ Откъс от публикацията в резюме " Probiotics are live microorganisms which, when administered in adequate amounts confer a health benefit on the host[6]. Specific probiotic strains have been shown to be effective in the prevention[7–9] and treatment[10] of atopic eczema, alleviating allergic inflammation both locally and systemically. The evidence of probiotic efficacy against allergic rhinitis and immunological sensitization predisposing to asthma is insufficient and contradictory at present. The previously studied probiotic strains or combinations of these may not have targeted airway allergies, or the populations studied may not have been responsive to immune modulation[9]. "Изследването е регистриран в www.clinicaltrials.gov под идентификатор NCT00746226.
============================================
Още едно медицинско проучване по темата тук :
Low Relative Abundances of the Mucolytic Bacterium Akkermansia muciniphila and Bifidobacterium spp. in Feces of Children with Autism▿†
"РЕЗЮМЕ
Стомашно-чревен смущения често се съобщава за лица с аутизъм. Ние използвахме количествен PCR в реално време анализ, за да се определи количествено фекални бактерии, които могат да повлияят на стомашно-чревния здраве при деца с и без аутизъм. По-ниски относителни abundances на видове Bifidobacteria и муколитичен бактерията Akkermansia muciniphila бяха открити при деца с аутизъм, като последният предполага слуз бариера променя."
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и тук : http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3153965/
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Akkermansia muciniphila: a Biomarker of Healthy Gut
January 17, 2015 by Leave a Comment
Recently, I’m interested in a gut bacterium – Akkermansia muciniphila. After reading all the papers on PubMed about it, I am going to wrap it up.
Akkermansia muciniphila (a species in the phylum Verrucomicriobia), first proposed in 2004 (1), is a mucin-degrading gut bacterium. It starts to colonize the GI tract in early life and within a year it reaches to a level close to that observed in adults (2). It’s abundant in the human intestine, accounting for approximately 1-3% of the total microbiota (3). It’s also abundant in other animals. It resides in mucus layer and grows on mucin as a sole carbon and nitrogen source (4).
By the way, what are mucins and what are the functions of the mucus layer? Here are the answers (4):
Mucins are a family of heavily glycosylated proteins that are the major organic components of the mucus layer, the protective layer covering the epithelial cells in many human and animal organs, including the entire gastro-intestinal tract.About 1% of the total fecal microbiota is able to use mucin as carbon source (in the gut, carbon sources are limited), including the genera Ruminococcus, Bifidobacterium, and Bacteroides species. This is like if you give me food, as a return, I will take care of you.
…
Mucus is present at the interface between many epithelial surfaces and their extracorporeal environments, including the oculo-rhino-otolaryngeal tracts, the respiratory tract, the gastrointestinal (GI) tract and the reproductive tract. Mucus is a complex viscous secretion, which often forms a continuous layer. The mucus is a highly hydrated gel (∼95% water) formed by large glycoproteins, called mucins, which further contains salts, lipids and proteins that are involved in defense such as defensins, growth factors, immunoglobulins, lysozym and trefoil factors and many other intestinal proteins. Humans secrete large volumes of mucus that amounts to approximately 10 liters of mucus per day. Mucus has many roles and can act as: (1) a lubricant, as in the airways and when facilitating the passage of food in the intestine; (2) a selective barrier by allowing passage of low molecular weight components, such as nutrients to the epithelial cells; and (3) a defense system that protects the underlying epithelial cells from mechanical damage or entrance of harmful substances of either chemical nature, such as drugs, toxins or heavy metals or biological nature, such as luminal pepsin, organic acids, pathogenic bacteria, viruses or parasites. (4) Another important function of mucus, which has come to light more recently, is to serve as a substrate for the growth, adhesion and protection of the trillions of microbial cells that are present in the lumen in the GI tract.
We know, the balance of the gut microbiota is critical for our health, but the balance is easily disturbed in our modern life. This of course affects Akkermansia muciniphila too. So what will cause Akkermansia muciniphila to decrease in the gut?
1. Obesity (5, 6, 7, 8). Obesity is associated with chronic low-grade inflammation. The mechanism goes like this: when Akkermansia muciniphila decreases, mucus layer becomes thinner and intestinal lining becomes weaker, leading to leaky gut, and then metabolic endotoxins enter the blood stream and cause chronic low-grade inflammation associated with obesity.
2. Type 2 diabetes (7, 9, 10). Why? Inflammation? The role of gut hormones (affected by gut microbiota) in glucose homeostasis? Bile acids (metabolized by gut microbiota) as signalling molecules involved in the regulation of biosynthetic and metabolic pathways in the gut and liver? Researchers are still exploring…
3. Inflammatory bowel diseases (IBD, both Crohn’s disease and ulcerative colitis) (11, 12, 13). The richness and diversity of gut microbiota decrease in IBD; Akkermansia is reduced many fold and even depleted.
4. Autism (14). Possible reasons: increased gut permeability or altered mucus turnover.
5. Acute appendicitis (15). Most cases of acute appendicitis are caused by local infection with Fusobacterium nucleatum/necrophorum. Main fecal microbiota such as Akkermansia muciniphila is inversely related to the severity of this disease.
6. Atopy (16). According to the study, “The intestinal microbiota of atopic children showed a significant depletion in members of the Clostridium cluster IV, Faecalibacterium prausnitzii, Akkermansia muciniphila and a corresponding increase of the relative abundance of Enterobacteriaceae,” which is pro-inflammatory.
7. Psoriatic arthritis and skin psoriasis (17). Patients with these problems have less diverse gut microbiota and a significant reduction in Akkermansia. The gut microbiota profile in patients with psoriatic arthritis is similar to that in patients with IBD and associated with changes in specific inflammatory proteins.
8. Nonalcoholic fatty liver disease (NAFLD) (18). There is an association between some gut microbiota and the gut-liver axis, but their mechanism of developing NAFLD is unknown. For Akkermansia muciniphila, it may due to its decrease causing a thinner mucus layer and leaky gut.
9. Old age (2).
As mentioned above, a decrease in Akkermansia muciniphila has an adverse effect on health. We need to have certain amount of Akkermansia muciniphila (1-3%) to keep the mucus layer in shape with respect to mucus production and thickness and to further maintain the integrity of the epithelial cells which lay underneath.
How can we increase Akkermansia muciniphila in the gut?
1. Gluten-free diet (19, 20). Dietary gluten can influence the composition of gut microbiota. When mice were fed gluten-free chows (GFC, see the figure below), their Akkermansia muciniphila increased; but adding gluten back reversed the effect. The two papers show that a gluten-free diet may reduce inflammation and the incidence of diabetes.
2. Prebiotics, such as arabinoxylan (a hemicellulose) or inulin (21) and xylooligosaccharides (XOS) (22). Prebiotics can increase the number of goblet cells (to secrete mucins) and mucus layer thickness, promoting the growth of Akekrmansia muciniphila.
3. Fasting (23, 24). A lack of food encourages the growth of Akkermansia muciniphila. Animals studies show that fasting increased Akkermansia muciniphila; however, total gut microbiota or overall diversity and short-chain fatty acids decreased.
4. Viable but not heat-killed Akkermansia muciniphila (oral administration) (5).
5. Medical treatment (This is not for everybody): metformin for type-2 diabetes (25), gastric bypass for obesity (26, 27), and some antibiotics (28) (I don’t get it. Because Akkermansia muciniphila has better survival skills?).
As for an increase or decrease in Akkermansia muciniphila, there are a couple of conflicting results of its studies:
Type 2 resistant starch (RS2), a dietary fiber from raw potato starch, green banana and high amylose corn: This study (29) shows that, mice fed RS2 (0, 18%, or 36%) had an increase in Akkermansia muciniphila. But when you look at its diagram, only a few mice fed 36% RS2 showed some Akkermansia muciniphila. Hmm, the researchers tossed out data. Thank Dr. Grace Liu from Animal Pharm for pointing this out to me. She has 6 or 7 human examples on her blog show Akkermansia muciniphila decreases 2-fold on RS2 on even low dosage of 10 g/day. This makes a lot of sense to me – they are human data and humans are not evolved to eat raw potato starch.
High-fat diet: Mice studies again. Akkermansia muciniphila grew well in the gut of mice fed a high-fat, fiber-free diet (30). Akkermansia muciniphila degrades mucin and can exist in the gut without any dietary fiber. It is perhaps not surprising that it increased. However, in another study (5), researchers observed a 46% thinner mucus layer and a 100-fold decrease of Ammermansia muciniphila in high-fat fed mice. More studies are needed to clarify these mixed results.
Akkermansia muciniphila has some promising hope for inflammatory and diet-related disorders. It may be one of the next generation of probiotics for our health.
(Courtesy of http://www.gezondheid.be)
В резюме : Akkermansia muciniphila ( в тип Verrucomicriobia) Тя започва да колонизира в стомашно-чревния тракт в началото на живота и в рамките на една година нормално трябва да достигне до ниво, близко до това при възрастните. Тя е широко разпространен в човешките черва, което представлява приблизително 1-3% от общото микрофлора. Тъй като по време на първата година от живота децата се ваксинират интензивно,което според много мед. доклади води до нарушаване на стомашно -чревната флора , не е възможно тази бактерия да достигне нужните нива в тялото. Именно в еднио от медицинските проучвания по горе е засегната темата за децата аутисти и нивата на тази бактерия в телата им. Глутенът пречи да се размножава въпросната бактерия и именно за това се препоръчва безглутенова диета при деца с аутизъм .
Нарушаването на нормалната стомашно-чревна флора и в частност -налаляване на нужното ниво на Akkermansia muciniphila бу могло да причини следните здравословни проблеми :
1. Затлъстяване
2. Диабет тип 2
3. Възпалителни заболявания на червата
4. Аутизъм ( Възможни причини: увеличена чревна пропускливост и качеството и количеството на слузтта .
5. остър апендицит
6. Атопия (Атопична кожа )
7. Псориатичен артрит и псориазис.
8. Чернодробно заболяване - не в следствие от употребата на алкохол .
9. Преждвременно остаряване ,влошаване качеството на живот
10.
Източник : http://www.biotanutrition.com/2015/01/17/akkermansia-muciniphila-a-biomarker-of-healthy-gut/
==========================================================
Ето тук медицински доклад на NCBI ,който обсъжда темата : Специфични пробиотици облекчат алергичен ринит по време на поленовия сезон . http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2710782/ Откъс от публикацията в резюме " Probiotics are live microorganisms which, when administered in adequate amounts confer a health benefit on the host[6]. Specific probiotic strains have been shown to be effective in the prevention[7–9] and treatment[10] of atopic eczema, alleviating allergic inflammation both locally and systemically. The evidence of probiotic efficacy against allergic rhinitis and immunological sensitization predisposing to asthma is insufficient and contradictory at present. The previously studied probiotic strains or combinations of these may not have targeted airway allergies, or the populations studied may not have been responsive to immune modulation[9]. "Изследването е регистриран в www.clinicaltrials.gov под идентификатор NCT00746226.
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